Stoichiometry | Chemistry | Visionlearning

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<li><a href="/en/library/earth-science/6/factors-that-control-earths-temperature/234">Factors that Control Earth's Temperature</a></li> <li><a href="/en/library/earth-science/6/circulation-in-the-atmosphere/255">Circulation in the Atmosphere</a></li> </ul> </div> <button class="accordion__button" id="acc-button-hazards" data-accordion="button" aria-controls="acc-panel-hazards" aria-expanded="false"> <span class="accordion__button__label"> Hazards </span> </button> <div class="accordion__panel" id="acc-panel-hazards" data-accordion="panel" aria-labelledby="acc-button-hazards" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/earth-science/6/natural-hazards-and-risk/288">Natural Hazards and Risk</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-history" data-accordion="button" aria-controls="acc-panel-earth-history" aria-expanded="false"> <span class="accordion__button__label"> Earth History </span> </button> <div class="accordion__panel" 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aria-controls="acc-panel-ecology" aria-expanded="false"> <span class="accordion__button__label"> Ecology </span> </button> <div class="accordion__panel" id="acc-panel-ecology" data-accordion="panel" aria-labelledby="acc-button-ecology" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/biodiversity-i/276">Biodiversity I</a></li> <li><a href="/en/library/environmental-science/61/biodiversity-ii/281">Biodiversity II</a></li> <li><a href="/en/library/environmental-science/61/ecosystem-services/279">Ecosystem Services</a></li> <li><a href="/en/library/environmental-science/61/population-biology/287">Population Biology</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-cycles" data-accordion="button" aria-controls="acc-panel-earth-cycles" aria-expanded="false"> <span class="accordion__button__label"> Earth Cycles </span> </button> <div class="accordion__panel" id="acc-panel-earth-cycles" data-accordion="panel" aria-labelledby="acc-button-earth-cycles" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/the-nitrogen-cycle/98">The Nitrogen Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-carbon-cycle/95">The Carbon Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-phosphorus-cycle/197">The Phosphorus Cycle</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/environmental-science/61/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-general-science" data-accordion="button" aria-controls="acc-panel-general-science" aria-expanded="false"> <span class="accordion__button__label"> General Science </span> </button> <div class="accordion__panel" id="acc-panel-general-science" data-accordion="panel" aria-labelledby="acc-button-general-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-methods" data-accordion="button" aria-controls="acc-panel-methods" aria-expanded="false"> <span class="accordion__button__label"> Methods </span> </button> <div class="accordion__panel" id="acc-panel-methods" data-accordion="panel" aria-labelledby="acc-button-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-scientific-method/45">The Scientific Method</a></li> </ul> </div> <button class="accordion__button" id="acc-button-measurement" data-accordion="button" aria-controls="acc-panel-measurement" aria-expanded="false"> <span class="accordion__button__label"> Measurement </span> </button> <div class="accordion__panel" id="acc-panel-measurement" data-accordion="panel" aria-labelledby="acc-button-measurement" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-metric-system/47">The Metric System</a></li> </ul> </div> <button class="accordion__button" id="acc-button-physical-properties" data-accordion="button" aria-controls="acc-panel-physical-properties" aria-expanded="false"> <span class="accordion__button__label"> Physical Properties </span> </button> <div class="accordion__panel" id="acc-panel-physical-properties" data-accordion="panel" aria-labelledby="acc-button-physical-properties" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/temperature/48">Temperature</a></li> <li><a href="/en/library/general-science/3/density-and-buoyancy/37">Density and Buoyancy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-math-in-science" data-accordion="button" aria-controls="acc-panel-math-in-science" aria-expanded="false"> <span class="accordion__button__label"> Math in Science </span> </button> <div class="accordion__panel" id="acc-panel-math-in-science" data-accordion="panel" aria-labelledby="acc-button-math-in-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-equations" data-accordion="button" aria-controls="acc-panel-equations" aria-expanded="false"> <span class="accordion__button__label"> Equations </span> </button> <div class="accordion__panel" id="acc-panel-equations" data-accordion="panel" aria-labelledby="acc-button-equations" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/unit-conversion/144">Unit Conversion</a></li> <li><a href="/en/library/math-in-science/62/linear-equations/194">Linear Equations</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-i/206">Exponential Equations I</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-ii/210">Exponential Equations II</a></li> <li><a href="/en/library/math-in-science/62/scientific-notation/250">Scientific Notation</a></li> <li><a href="/en/library/math-in-science/62/measurement/257">Measurement</a></li> </ul> </div> <button class="accordion__button" id="acc-button-statistics" data-accordion="button" aria-controls="acc-panel-statistics" aria-expanded="false"> <span class="accordion__button__label"> Statistics </span> </button> <div class="accordion__panel" id="acc-panel-statistics" data-accordion="panel" aria-labelledby="acc-button-statistics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/introduction-to-descriptive-statistics/218">Introduction to Descriptive Statistics</a></li> <li><a href="/en/library/math-in-science/62/introduction-to-inferential-statistics/224">Introduction to Inferential Statistics</a></li> <li><a href="/en/library/math-in-science/62/statistical-techniques/239">Statistical Techniques</a></li> </ul> </div> <button class="accordion__button" id="acc-button-trigonometric-functions" data-accordion="button" aria-controls="acc-panel-trigonometric-functions" aria-expanded="false"> <span class="accordion__button__label"> Trigonometric Functions </span> </button> <div class="accordion__panel" id="acc-panel-trigonometric-functions" data-accordion="panel" aria-labelledby="acc-button-trigonometric-functions" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/wave-mathematics/131">Wave Mathematics</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-physics" data-accordion="button" aria-controls="acc-panel-physics" aria-expanded="false"> <span class="accordion__button__label"> Physics </span> </button> <div class="accordion__panel" id="acc-panel-physics" data-accordion="panel" aria-labelledby="acc-button-physics" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-light-and-optics" data-accordion="button" aria-controls="acc-panel-light-and-optics" aria-expanded="false"> <span class="accordion__button__label"> Light and Optics </span> </button> <div class="accordion__panel" id="acc-panel-light-and-optics" data-accordion="panel" aria-labelledby="acc-button-light-and-optics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/the-nature-of-light/132">The Nature of Light</a></li> <li><a href="/en/library/physics/24/electromagnetism-and-light/138">Electromagnetism and Light</a></li> </ul> </div> <button class="accordion__button" id="acc-button-mechanics" data-accordion="button" aria-controls="acc-panel-mechanics" aria-expanded="false"> <span class="accordion__button__label"> Mechanics </span> </button> <div class="accordion__panel" id="acc-panel-mechanics" data-accordion="panel" aria-labelledby="acc-button-mechanics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/defining-energy/199">Defining Energy</a></li> <li><a href="/en/library/physics/24/waves-and-wave-motion/102">Waves and Wave Motion</a></li> <li><a href="/en/library/physics/24/gravity/118">Gravity</a></li> <li><a href="/en/library/physics/24/thermodynamics-i/200">Thermodynamics I</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-process-of-science" data-accordion="button" aria-controls="acc-panel-process-of-science" aria-expanded="false"> <span class="accordion__button__label"> Process of Science </span> </button> <div class="accordion__panel" id="acc-panel-process-of-science" data-accordion="panel" aria-labelledby="acc-button-process-of-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-introduction" data-accordion="button" aria-controls="acc-panel-introduction" aria-expanded="false"> <span class="accordion__button__label"> Introduction </span> </button> <div class="accordion__panel" id="acc-panel-introduction" data-accordion="panel" aria-labelledby="acc-button-introduction" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-process-of-science/176">The Process of Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-the-culture-of-science" data-accordion="button" aria-controls="acc-panel-the-culture-of-science" aria-expanded="false"> <span class="accordion__button__label"> The Culture of Science </span> </button> <div class="accordion__panel" id="acc-panel-the-culture-of-science" data-accordion="panel" aria-labelledby="acc-button-the-culture-of-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-nature-of-scientific-knowledge/185">The Nature of Scientific Knowledge</a></li> <li><a href="/en/library/process-of-science/49/scientists-and-the-scientific-community/172">Scientists and the Scientific Community</a></li> <li><a href="/en/library/process-of-science/49/scientific-ethics/161">Scientific Ethics</a></li> <li><a href="/en/library/process-of-science/49/scientific-institutions-and-societies/162">Scientific Institutions and Societies</a></li> </ul> </div> <button class="accordion__button" id="acc-button-ideas-in-science" data-accordion="button" aria-controls="acc-panel-ideas-in-science" aria-expanded="false"> <span class="accordion__button__label"> Ideas in Science </span> </button> <div class="accordion__panel" id="acc-panel-ideas-in-science" data-accordion="panel" aria-labelledby="acc-button-ideas-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/theories-hypotheses-and-laws/177">Theories, Hypotheses, and Laws</a></li> <li><a href="/en/library/process-of-science/49/scientific-controversy/181">Scientific Controversy</a></li> <li><a href="/en/library/process-of-science/49/creativity-in-science/182">Creativity in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-research-methods" data-accordion="button" aria-controls="acc-panel-research-methods" aria-expanded="false"> <span class="accordion__button__label"> Research Methods </span> </button> <div class="accordion__panel" id="acc-panel-research-methods" data-accordion="panel" aria-labelledby="acc-button-research-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-practice-of-science/148">The Practice of Science</a></li> <li><a href="/en/library/process-of-science/49/experimentation-in-scientific-research/150">Experimentation in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/description-in-scientific-research/151">Description in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/comparison-in-scientific-research/152">Comparison in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153">Modeling in Scientific Research</a></li> </ul> </div> <button class="accordion__button" id="acc-button-data" data-accordion="button" aria-controls="acc-panel-data" aria-expanded="false"> <span class="accordion__button__label"> Data </span> </button> <div class="accordion__panel" id="acc-panel-data" data-accordion="panel" aria-labelledby="acc-button-data" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/data-analysis-and-interpretation/154">Data Analysis and Interpretation</a></li> <li><a href="/en/library/process-of-science/49/uncertainty-error-and-confidence/157">Uncertainty, Error, and Confidence</a></li> <li><a href="/en/library/process-of-science/49/statistics-in-science/155">Statistics in Science</a></li> <li><a href="/en/library/process-of-science/49/using-graphs-and-visual-data-in-science/156">Using Graphs and Visual Data in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-communication" data-accordion="button" aria-controls="acc-panel-scientific-communication" aria-expanded="false"> <span class="accordion__button__label"> Scientific Communication </span> </button> <div class="accordion__panel" id="acc-panel-scientific-communication" data-accordion="panel" aria-labelledby="acc-button-scientific-communication" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/understanding-scientific-journals-and-articles/158">Understanding Scientific Journals and Articles</a></li> <li><a href="/en/library/process-of-science/49/utilizing-the-scientific-literature/173">Utilizing the Scientific Literature</a></li> <li><a href="/en/library/process-of-science/49/peer-review-in-scientific-publishing/159">Peer Review in Scientific Publishing</a></li> <li><a href="/en/library/process-of-science/49/the-how-and-why-of-scientific-meetings/186">The How and Why of Scientific Meetings</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-scientists-and-research" data-accordion="button" aria-controls="acc-panel-scientists-and-research" aria-expanded="false"> <span class="accordion__button__label"> Scientists and Research </span> </button> <div class="accordion__panel" id="acc-panel-scientists-and-research" data-accordion="panel" aria-labelledby="acc-button-scientists-and-research" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/scientists-and-research/58/from-stable-chromosomes-to-jumping-genes/184">From Stable Chromosomes to Jumping Genes</a></li> <li><a href="/en/library/scientists-and-research/58/an-elegant-experiment-to-test-the-process-of-dna-replication/187">An Elegant Experiment to Test the Process of DNA Replication</a></li> <li><a href="/en/library/scientists-and-research/58/the-founding-of-neuroscience/233">The Founding of Neuroscience</a></li> <li><a href="/en/library/scientists-and-research/58/tracking-endangered-jaguars-across-the-border/189">Tracking Endangered Jaguars across the Border</a></li> <li><a href="/en/library/scientists-and-research/58/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> <li><a href="/en/library/scientists-and-research/58/revolutionizing-medicine-with-monoclonal-antibodies/220">Revolutionizing Medicine with Monoclonal Antibodies</a></li> <li><a href="/en/library/scientists-and-research/58/uncovering-the-mysteries-of-chronic-mountain-sickness/238">Uncovering the Mysteries of Chronic Mountain Sickness</a></li> </ul> </div> <button class="accordion__button" id="acc-button-profiles-in-science" data-accordion="button" aria-controls="acc-panel-profiles-in-science" aria-expanded="false"> <span class="accordion__button__label"> Profiles in Science </span> </button> <div class="accordion__panel" id="acc-panel-profiles-in-science" data-accordion="panel" aria-labelledby="acc-button-profiles-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/luis-e.-miramontes/232">Luis E. Miramontes</a></li> <li><a href="/en/library/scientists-and-research/58/bernardo-houssay/237">Bernardo Houssay</a></li> <li><a href="/en/library/scientists-and-research/58/craig-lee/256">Craig Lee</a></li> <li><a href="/en/library/scientists-and-research/58/david-ho/241">David Ho</a></li> <li><a href="/en/library/scientists-and-research/58/louis-tompkins-wright/244">Louis Tompkins Wright</a></li> <li><a href="/en/library/scientists-and-research/58/carlos-j.-finlay/217">Carlos J. Finlay</a></li> <li><a href="/en/library/scientists-and-research/58/cecilia-payne/290">Cecilia Payne</a></li> <li><a href="/en/library/scientists-and-research/58/jazmin-scarlett/291">Jazmin Scarlett</a></li> <li><a href="/en/library/scientists-and-research/58/ramari-stewart/292">Ramari Stewart</a></li> <li><a href="/en/library/scientists-and-research/58/johnson-cerda/300">Johnson Cerda</a></li> <li><a href="/en/library/scientists-and-research/58/ellen-ochoa/201">Ellen Ochoa</a></li> <li><a href="/en/library/scientists-and-research/58/ruth-benerito/205">Ruth Benerito</a></li> <li><a href="/en/library/scientists-and-research/58/franklin-chang-díaz/219">Franklin Chang Díaz</a></li> <li><a href="/en/library/scientists-and-research/58/percy-lavon-julian/221">Percy Lavon Julian</a></li> <li><a href="/en/library/scientists-and-research/58/luis-walter-alvarez/229">Luis Walter Alvarez</a></li> <li><a href="/en/library/scientists-and-research/58/france-anne-dominic-córdova/230">France Anne-Dominic Córdova</a></li> </ul> </div> </div> </div> </div> </div> </li> <li>  <button class="button" data-toggle="dropdown">Chemistry </button> <div class="nav__dropdown box-shadow-1 padding-1"> <div class="accordion accordion--secondary font-size-sm"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-sub-button-atomic-theory-and-structure" data-accordion="button" aria-controls="acc-sub-panel-atomic-theory-and-structure" aria-expanded="false"> <span class="accordion__button__label"> Atomic Theory and Structure </span> </button> <div class="accordion__panel" id="acc-sub-panel-atomic-theory-and-structure" data-accordion="panel" aria-labelledby="acc-sub-button-atomic-theory-and-structure" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/chemistry/1/early-ideas-about-matter/49">Early Ideas about Matter</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-i/52">The Periodic Table of Elements I</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-ii/296">The Periodic Table of Elements II</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-iii/297">The Periodic Table of Elements III</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-iv/298">The Periodic Table of Elements IV</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-v/299">The Periodic Table of Elements V</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-i/50">Atomic Theory I</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-ii/51">Atomic Theory II</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-iii/223">Atomic Theory III</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-iv/231">Atomic Theory IV</a></li> <li><a href="/en/library/chemistry/1/the-mole-and-atomic-mass/53">The Mole and Atomic Mass</a></li> </ul> </div> <button class="accordion__button" 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id="skip-header-content"> <div class="margin-bottom-5"> <div class="container narrow wide--lg margin-y-4"> <article class="module"> <header class="module__header"> <span class="subcategory"> <strong><em>Chemical Relationships</em></strong> </span> <h1>Stoichiometry: <sub><em>The proportional nature of chemical reactions</em></sub></h1> <p class="byline">by Robin Marks, M.A., Anthony Carpi, Ph.D.</p> </header> <nav class="module__tabs"> <ul class="tabs-nav tabs-nav--pill tabs-nav--horizontal--md library"> <li> <a href="/en/library/chemistry/1/stoichiometry/270/reading" class="is-active" aria-current="page" >Reading</a> </li> <li> <a href="/en/library/chemistry/1/stoichiometry/270/quiz" >Quiz</a> </li> <li> <a href="/en/library/chemistry/1/stoichiometry/270/resources" >Teach with this</a> </li> </ul> </nav> <hr class="module__divider" />  <div class="module__tools"> <aside class="module__tools__container border-radius box-shadow-1"> <div class="tabs tabs--toggle-mobile--lg" role="tablist"> <ul class="tab__buttons"> <li> <button class="button button--icon-over-text" aria-label="In this module" aria-controls="tab-panel-module__tools" aria-selected="true" role="tab"> <span class="button__icon"> <span class="icon icon-list" aria-hidden="true"></span> </span> <span class="button__text">Contents</span> </button> </li> <li> <button class="button button--icon-over-text" aria-controls="tab-panel-toggle-terms" aria-selected="false" role="tab"> <span class="button__icon"> <span class="icon icon-glossary-highlight"></span> </span> <span class="button__text">Glossary Terms</span> </button> </li> </ul> <div class="tabs__panel shown" id="tab-panel-module__tools" aria-labelledby="tab-button-module__tools" role="tabpanel"> <div class="table-of-contents"> <p class="table-of-contents__title"> Table of Contents </p> <ul class="table-of-contents__nav"> <li> <ul> <li><a href="/en/library/chemistry/1/stoichiometry/270#toc2_1">Stoichiometry predicts the amount of product produced</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/stoichiometry/270#toc2_2">From s’mores to manufacturing: Real-world stoichiometry</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/stoichiometry/270#toc2_3">Mole Ratios: Applying stoichiometry to the production of fertilizer</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/stoichiometry/270#toc2_4">Limiting Reactant: The first reactant used up limits the amount of product</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/stoichiometry/270#toc2_5">Summary</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/stoichiometry/270#toc2_6">Key Concepts</a> </li> </ul> </li> </ul> </div> </div> <div class="tabs__panel" id="tab-panel-toggle-terms" aria-labelledby="tab-button-toggle-terms" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="termsToggleSwitch" id="terms-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Highlight Glossary Terms </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate glossary term highlighting to easily identify key terms within the module. Once highlighted, you can click on these terms to view their definitions. </em> </p> </div> </div> <div class="glossary-container"></div> </div> <div class="tabs__panel" id="tab-panel-toggle-ngss" aria-labelledby="tab-button-toggle-ngss" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="ngssToggleSwitch" id="ngss-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Show NGSS Annotations </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate NGSS annotations to easily identify NGSS standards within the module. Once highlighted, you can click on them to view these standards. </em> </p> </div> </div> <div class="ngss-container"></div> </div> </div> </aside> <div class="margin-3"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-9561344156007092" data-ad-slot="7634263342" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </div>     <div class="module__main"> <div class="module__main__container"> <div class="accordion"> </div> <section> <p>It’s nearly the start of the school year, and you’ve gathered 10 friends for an end-of-semester bonfire. What would a bonfire be without s’mores? You pack supplies, making sure you have enough to make one s’more for everyone. </p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox="image"> <img src="/img/library/modules/mid270/Image/VLObject-12091-190826100814.jpg" alt=" Smore Better " /> </button> </figure> </div> <p>You can think of making a sâmore as a chemical equation (see our <a href="/en/library/Chemistry/1/Chemical-Equations/268">Chemical Equations</a> module for more on those):<div class="figure"><figure> $$\text{2 Graham crackers } + \text{ 1 piece of chocolate } + \text{ 4 mini-marshmallows } \rightarrow \text{ 1 s'more}$$ </figure></div><p>Just as with a chemical equation, the coefficients in front of the "reactants" and "products" show the proportions in which they react to produce the desired productâone s'more.</p><p>So, to make 10 s'mores, you would need:</p><div class="figure"><figure> $$\text{20 Graham crackers } + \text{ 10 piece of chocolate } + \text{ 40 mini-marshmallows } \rightarrow \text{ 10 s'more}$$ </figure></div></p><p>Congratulations, you’ve just made it through your first exercise in what chemists call <mark class="term" data-term="Stoichiometry" data-term-def="The proportional relationship (ratio) between reactants and products in a chemical equation." data-term-url="/en/glossary/view/Stoichiometry/12126">stoichiometry</mark>. This mouthful of a term was coined in the 1790s by chemist Jeremias Benjamin Richter, who became fascinated by the proportional mathematics of combining chemicals, convinced that it held clues to the nature of <mark class="term" data-term="matter" data-term-def="The substance that makes up physical objects." data-term-url="/en/glossary/view/matter/8264">matter</mark> (which it does indeed; Dalton drew on this math to devise his early atomic <mark class="term" data-term="theory" data-term-def="A scientific theory is an explanation inferred from multiple lines of evidence for some broad aspect of the natural world and&hellip;" data-term-url="/en/glossary/view/theory/4854">theory</mark>, described in depth in our module <a href="/en/library/Chemistry/1/Early-Ideas-about-Matter/49">Early Ideas about Matter: From Democritus to Dalton.</a> Richter combined the Greek words stoicheion, which <mark class="term" data-term="mean" data-term-def="In statistics, mean commonly refers to the arithmetic mean, also called the average, which is one measure of the mid-point of&hellip;" data-term-url="/en/glossary/view/mean/4221">means</mark> “element,” and metron, which means “measure.” In other words, stoichiometry is a way of measuring the amount of each <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> combining in a <mark class="term" data-term="chemical reaction" data-term-def="A process in which atoms and molecules recombine by forming or breaking chemical bonds. Chemical reactions form new products that&hellip;" data-term-url="/en/glossary/view/chemical+reaction/1547">chemical reaction</mark>, in our case, the amounts of reactant (20 graham crackers, 10 pieces of chocolate and 30 mini-marshmallows) that in turn predict the amount of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> (10 s’mores), or vice versa. <p><p>Stoichiometry may seem like a complicated word, but it’s a fairly straightforward concept when you apply it to chemical equations: the proportions expressed in a chemical equation (the coefficients) can be used to predict how much <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> will be produced from a given measure of <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactants</mark>.</p> <div class="container margin-y-4 text-align-center"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:inline-block;width:300px;height:250px" data-ad-client="ca-pub-9561344156007092" data-ad-slot="9090201191"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </section> <section id="toc2_1"><h3>Stoichiometry predicts the amount of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> produced</h3><p>For example, we used stoichiometry to determine how many s'more "reactants" we would need to make 10 s'mores. We can also use stoichiometry to predict how much product weâll get with the amount of each reactant we have. If we have lots and lots of chocolate and marshmallows but only 12 graham crackers, how many s'mores can we make?<p>Again, our equation is:</p><div class="figure"><figure> $$\text{2 Graham crackers } + \text{ 1 piece of chocolate } + \text{ 4 mini-marshmallows } \rightarrow \text{ 1 s'more}$$ </figure></div><p>If we have 12 graham crackers, that's enough to make 6 s'mores. It doesn't matter how much extra chocolate we have, because without the graham crackers, it isn't a s'more. </p><p>So the mole ratio of graham crackers to s'mores produced is two to one, or 2:1. </p></p></section> <section id="toc2_2"><h3>From s’mores to manufacturing: Real-world stoichiometry</h3><p>Using the same concept of <mark class="term" data-term="mole" data-term-def="An amount equal to Avogadro's number, or 6.02 × 10<sup>23</sup>. One mole of atoms is equal to 6.02 × 10<sup>23</sup> atoms." data-term-url="/en/glossary/view/mole/1515">mole</mark> <mark class="term" data-term="ratio" data-term-def="The relationship between two or more quantities; relative amounts of two or more values expressed as a proportion." data-term-url="/en/glossary/view/ratio/8556">ratios</mark> as explained above, <mark class="term" data-term="Stoichiometry" data-term-def="The proportional relationship (ratio) between reactants and products in a chemical equation." data-term-url="/en/glossary/view/Stoichiometry/12126">stoichiometry</mark> is used to figure out how much <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> is needed to make a desired quantity of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> in a laboratory or manufacturing facility. An important industrial example is the production of nitrogen-based fertilizer, which provides important <mark class="term" data-term="nutrient" data-term-def="A chemical substance (e.g., minerals, vitamins, proteins) that is needed by an organism to survive and grow. See also: macronutrient and micronutrient." data-term-url="/en/glossary/view/nutrient/7058">nutrients</mark> to the <mark class="term" data-term="soil" data-term-def="The loose top layer of Earth’s surface where plants grow, made up of particles of rocks, minerals, and organic material." data-term-url="/en/glossary/view/soil/8563">soil</mark> and allows modern farmers to grow more food per acre. </p><p>For centuries, farmers have understood the importance of adding <mark class="term" data-term="nutrient" data-term-def="A chemical substance (e.g., minerals, vitamins, proteins) that is needed by an organism to survive and grow. See also: macronutrient and micronutrient." data-term-url="/en/glossary/view/nutrient/7058">nutrients</mark> to the <mark class="term" data-term="soil" data-term-def="The loose top layer of Earth’s surface where plants grow, made up of particles of rocks, minerals, and organic material." data-term-url="/en/glossary/view/soil/8563">soil</mark> in which they grow crops, but prior to the 1900s they were limited to using animal manure or expensive, naturally occurring <mark class="term" data-term="mineral" data-term-def="A naturally formed, inorganic solid with a specific chemical composition and characteristic crystal structure. Examples of minerals include quartz (SiO<sub>2</sub>), salt&hellip;" data-term-url="/en/glossary/view/mineral/2978">mineral</mark> deposits as fertilizer. In the 1840s, the German chemist Justus von Liebig identified nitrogen as fertilizer’s key ingredient. However, despite the abundance of nitrogen in the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark>, there was no easy way to convert nitrogen to a form that could be taken up by plants.</p><p>This all changed in the early 1900s when the German chemist <mark class="term" data-term="Fritz Haber" data-term-def="German chemist born in Breslau (1868-1934). Haber began his career in chemistry with investigations on the decomposition and combustion of hydrocarbons.&hellip;" data-term-url="/en/glossary/view/Haber%2C+Fritz/4532">Fritz Haber</mark> invented a chemical <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark> for converting nitrogen to ammonia (NH<sub>3</sub>), the <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compound</mark> that often gives household cleaners their characteristic smell, and which plants can use as a source of nitrogen. His initial <mark class="term" data-term="method" data-term-def="A procedure or process; a systematic way of performing a task or conducting research." data-term-url="/en/glossary/view/method/8238">method</mark> was only economical on a small <mark class="term" data-term="scale" data-term-def="An instrument for measuring heat energy or weight in which units are marked at intervals; a system for quantifying heat energy&hellip;" data-term-url="/en/glossary/view/scale/8536">scale</mark>, so Haber worked with a German colleague, Carl Bosch, to adapt this process to <mark class="term" data-term="work" data-term-def="A process that occurs when a force acts over a distance, as when an object is moved. Work equals the multiple&hellip;" data-term-url="/en/glossary/view/work/1502">work</mark> at an industrial scale. The Haber-Bosch process is sometimes referred to as one of the most significant inventions of the 20th century, and it led to Haber winning the <mark class="term" data-term="Nobel Prize" data-term-def="Awards made annually, beginning in 1901, from funds originally established by Alfred B. Nobel for outstanding achievement in physics, chemistry, medicine&hellip;" data-term-url="/en/glossary/view/Nobel+Prize/3843">Nobel Prize</mark> in Chemistry in 1918. In its equation form, the Haber-Bosch process is relatively simple:</p><div class="figure"><figure> $$N_2 + 3H_2 \rightarrow 2NH_3$$ </figure></div><p>The ability to perform this simple <mark class="term" data-term="reaction" data-term-def="A chemical change when substances come into contact with each other." data-term-url="/en/glossary/view/reaction/8263">reaction</mark> on a large <mark class="term" data-term="scale" data-term-def="An instrument for measuring heat energy or weight in which units are marked at intervals; a system for quantifying heat energy&hellip;" data-term-url="/en/glossary/view/scale/8536">scale</mark> had important historical consequences. Cheap ammonia provided an avenue to widely available inexpensive fertilizers, which created a boom in agriculture (and an associated increase in population) in the 20th century. And it indirectly prolonged World War I by providing Germany with an inexpensive source of the nitrogen necessary to make gunpowder. Some scientists have more recently questioned whether the Haber-Bosch <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark> is a sustainable practice, given the environmental impact of agriculture and a growing <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark>, as well as the fact that considerable <mark class="term" data-term="energy" data-term-def="An abstract property defined as the capacity to do work. The basic forms of energy include chemical, electrical, mechanical, nuclear, and&hellip;" data-term-url="/en/glossary/view/energy/1497">energy</mark> is required to generate the hydrogen <mark class="term" data-term="gas" data-term-def="The state of matter characterized by its non-condensed nature and ability to flow. Unlike liquids, molecules within a gas remain far&hellip;" data-term-url="/en/glossary/view/gas/8725">gas</mark>. </p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox="image"> <img src="/img/library/modules/mid270/Image/VLObject-12122-191210011248.png" alt="Spraying rice fields with fertilizer. The manufacturing of nitrogen-based fertilizers relies on stoichiometry to calculate how much starting material (N2 and H2) is needed to produce the desired amount of ammonia (NH3) to be used in the fertilizer." /> </button> <figcaption> <p>Spraying rice fields with fertilizer. The manufacturing of nitrogen-based fertilizers relies on stoichiometry to calculate how much starting material (N2 and H2) is needed to produce the desired amount of ammonia (NH3) to be used in the fertilizer.</p> <span class="credit">image ©Jan Amiss</span> </figcaption> </figure> </div> </section> <section id="toc2_3"><h3>Mole Ratios: Applying <mark class="term" data-term="Stoichiometry" data-term-def="The proportional relationship (ratio) between reactants and products in a chemical equation." data-term-url="/en/glossary/view/Stoichiometry/12126">stoichiometry</mark> to the production of fertilizer</h3><p>Let’s apply our <mark class="term" data-term="Stoichiometry" data-term-def="The proportional relationship (ratio) between reactants and products in a chemical equation." data-term-url="/en/glossary/view/Stoichiometry/12126">stoichiometry</mark> discussion here and imagine that an agricultural company needs to manufacture 1,500 kilograms of NH<sub>3</sub> to meet the demand for fertilizer. How much N<sub>2</sub> and H<sub>2</sub> would they need to start with? </p><p>Again, the equation is:<div class="figure"><figure> $$N_2 + 3H_2 \rightarrow 2NH_3$$ </figure></div></p><p>Looking at the equation, we see that the mole ratio of N<sub>2</sub> required to produce NH<sub>3</sub> is:<div class="figure"><figure> $$\frac{(\text{1 mol } N_2)}{(\text{2 mol } NH_3)}$$ </figure></div></p><p>Now we’ll use this <mark class="term" data-term="mole" data-term-def="An amount equal to Avogadro's number, or 6.02 × 10<sup>23</sup>. One mole of atoms is equal to 6.02 × 10<sup>23</sup> atoms." data-term-url="/en/glossary/view/mole/1515">mole</mark> <mark class="term" data-term="ratio" data-term-def="The relationship between two or more quantities; relative amounts of two or more values expressed as a proportion." data-term-url="/en/glossary/view/ratio/8556">ratio</mark> to determine how much <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> we need to start with to make 1,500 kilograms of ammonia.</p> <p>First, a reminder: whenever we are calculating amounts of substance in a <mark class="term" data-term="reaction" data-term-def="A chemical change when substances come into contact with each other." data-term-url="/en/glossary/view/reaction/8263">reaction</mark>, we have to convert the <mark class="term" data-term="mass" data-term-def="A fundamental property of matter which is a numerical measure of the inertia of an object or the amount of matter&hellip;" data-term-url="/en/glossary/view/mass/3417">mass</mark> of each substance into moles. Why? Because the substances involved don’t have equal <mark class="term" data-term="weight" data-term-def="A measure of the force exerted on an object by a gravitational field. The weight of an object equals its mass&hellip;" data-term-url="/en/glossary/view/weight/3418">weights</mark>. Think of it in terms of the s’more: 1 piece of chocolate weighs a lot more than 1 mini-marshmallow. If we used mass in the equation instead of number of pieces, we might say that one s’more requires 1 gram of chocolate and 4 grams of mini-marshmallows. But in reality, that would amount to one piece of chocolate and about 50 mini-marshmallows! (For more on converting from grams to moles, see our module about the mole and <mark class="term" data-term="atomic mass" data-term-def="The average mass of an atom of an element, usually expressed in atomic mass units. The term is often used interchangeably&hellip;" data-term-url="/en/glossary/view/atomic+mass/1513">atomic mass</mark>.) </p><p>So, we know that we want to make 1,500 kg of NH<sub>3</sub>, Let's start by converting kilograms to grams as follows:<div class="figure"><figure> $$\text{1,500 kg of } NH_3 \text{ x 1,000 g/kg = 1,500,000 g of } NH_3$$ </figure></div><p>Then, we need to calculate how many moles that is. To do that, we multiply the molecular mass of NH<sub>3</sub> (17 g per mole) by the number of grams, setting the equation up so that the grams cancel and the answer is in moles. We see that:</p></p><div class="figure"><figure> $$\text{1,500,000 g } {NH_3} \times \frac{(\text{1 mol } NH_3)}{(\text{17 g }NH_3)} = \text{88,325 mol } {NH_3}$$ <p>Next, we can use the mole ratio to figure out how many moles of N<sub>2</sub> will be needed. Since we need 1 mole of N<sub>2</sub> to produce 2 moles of NH<sub>3</sub>, we use that mole ratio to determine how many moles of N<sub>2</sub> will be needed to produce 88,235 moles of NH<sub>3</sub>:</p></figure></div> <div class="container margin-y-4 text-align-center"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:inline-block;width:300px;height:250px" data-ad-client="ca-pub-9561344156007092" data-ad-slot="3321739899"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> <div class="figure"><figure> $$\text{88,235 mol } {NH_3} \times \frac{(\text{1 mol } N_2)}{(\text{2 mol }NH_3)} = \text{44,117 mol } {N_2}$$ <p>Now, use the molecular mass of N<sub>2</sub> to figure out how many grams of N<sub>2</sub> are required, then convert the grams of N<sub>2</sub> to kg of N<sub>2</sub>, since that's the units we want for our answer:</p><div class="figure"><figure> $$\text{44,117 mol } {N_2} \times \frac{(\text{28 g } N_2)}{(\text{1 mol }N_2)} = \text{882,340 g } {N_2}\text{, or 882,340 kg}$$ </figure></div></figure></div><p>Now that we know how many kilograms of N<sub>2</sub> we would need, we can use the mole ratio of the reactants (N<sub>2</sub> and H<sub>2</sub>) to figure out how many moles of H<sub>2</sub> are required.<p>Remember, the equation states:</p><div class="figure"><figure> $$N_2 + 3H_2 \rightarrow 2NH_3$$ </figure></div></p><p>The mole ratio for H<sub>2</sub> to N<sub>2</sub> is 3 to 1. So, for every mole of nitrogen, we'll need three times as many moles of hydrogen:<div class="figure"><figure> $$\frac{(\text{3 mol }H_2)}{(\text{1 mol } N_2)}$$ </figure></div><p>Remember, we need to calculate how many moles of hydrogen are needed, and then convert those moles of hydrogen into grams of hydrogen. Using the moles of nitrogen we calculated above, we can get kg of H<sub>2</sub>:</p><div class="figure"><figure> $$\text{44,117 mol } N_2 \times \frac{(\text{3 mol }H_2)}{(\text{1 mol } N_2)} \times \frac{(\text{2 g } H_2)}{(\text{1 mol }H_2)} = \text{264,702 g }H_2\text{, or 264,702 kg}$$ </figure></div></p><p>This is important information for the fertilizer manufacturer. While nitrogen is readily available from the air, hydrogen <mark class="term" data-term="gas" data-term-def="The state of matter characterized by its non-condensed nature and ability to flow. Unlike liquids, molecules within a gas remain far&hellip;" data-term-url="/en/glossary/view/gas/8725">gas</mark> is not. So the manufacturer would likely have to purchase the hydrogen gas, which is expensive to generate, potentially explosive, and difficult to transport and store. Therefore, the manufacturer needs to know precisely how much hydrogen gas is required.</p></section> <section id="toc2_4"><h3>Limiting Reactant: The first <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> used up limits the amount of product</h3><p>In the case above, the manufacturer will have an unlimited amount of nitrogen gas, but a precise amount of hydrogen gas. Therefore, the amount of hydrogen gas will limit the amount of ammonia that can be made (just like the number of graham crackers can limit the number of s'mores that can be made).<p>We would say that hydrogen is the limiting reactant, meaning that this is the reactant that will be used up first. As a result, the amount of it will determine how much product is produced. Determining how much reactant is required to produce a specific amount of product is one of the most important applications of stoichiometry.</p><p>We'll illustrate this first with the s'mores. Let's say you have the following amounts of s'more "reactants":</p><p>120 graham crackers</p><p>70 pieces of chocolate</p><p>200 mini-marshmallows</p><p>Here, again, is the s'mores equation:</p><div class="figure"><figure> $$\text{2 Graham crackers } + \text{ 1 piece of chocolate } + \text{ 4 mini-marshmallows } \rightarrow \text{ 1 s'more}$$ </figure></div><p>How many s'mores can you make from your reactants? That will depend on the limiting reactant, the one which will run out first. To determine with reactant is limiting, you will first need to calculate how many s'mores you can make with each of the reactants. You can do this using the mole ratio:</p></p><p>Limiting <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> is an important concept in any manufacturing <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark>. A manufacturer knows they want to make a certain amount of a specific <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark>, and will purchase the reactants accordingly. In many cases, it is more economical to make the most expensive reactant be the limiting one, reducing the cost of excess and waste.</p> <p>Silver nitrate is a good example. This <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compound</mark>, AgNO<sub>3</sub>, has been used since ancient times as a disinfectant and wound-healing agent. Today it is used in bandages and other medical applications, as well as water purification. It can be easily made by reacting pure silver with nitric <mark class="term" data-term="acid" data-term-def="Generally, a substance that reacts with bases to form a salt, several different definitions of acids have been proposed by different&hellip;" data-term-url="/en/glossary/view/acid/1573">acid</mark>, according to the equation:</p><div class="figure"><figure> $$3Ag + 4HNO_3 \rightarrow 3AgNO_3 + 2H_2O + NO$$ </figure></div> <p>Silver is a much more expensive <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> than nitric <mark class="term" data-term="acid" data-term-def="Generally, a substance that reacts with bases to form a salt, several different definitions of acids have been proposed by different&hellip;" data-term-url="/en/glossary/view/acid/1573">acid</mark>, so someone using it to produce silver nitrate will probably want to make silver the <mark class="term" data-term="limiting reactant" data-term-def="The reactant which, according to the mole ratio of the chemical equation, will be used up first and determines the amount&hellip;" data-term-url="/en/glossary/view/limiting+reactant/1570">limiting reactant</mark>.</p> <p>By starting with a set amount of each <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark>, you can determine not only the <mark class="term" data-term="limiting reactant" data-term-def="The reactant which, according to the mole ratio of the chemical equation, will be used up first and determines the amount&hellip;" data-term-url="/en/glossary/view/limiting+reactant/1570">limiting reactant</mark> but also the <mark class="term" data-term="mass" data-term-def="A fundamental property of matter which is a numerical measure of the inertia of an object or the amount of matter&hellip;" data-term-url="/en/glossary/view/mass/3417">mass</mark> of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> that will be produced and the amount of reactant that remains in excess.</p> <p>Let’s say we start with 150g of silver and 150 g of nitric <mark class="term" data-term="acid" data-term-def="Generally, a substance that reacts with bases to form a salt, several different definitions of acids have been proposed by different&hellip;" data-term-url="/en/glossary/view/acid/1573">acid</mark>. How much AgNO<sub>3</sub> can we make, and which <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> is the limiting one?</p> <p><p>To find the answer takes a few steps:<p?> <p>1) convert each <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> to <mark class="term" data-term="mole" data-term-def="An amount equal to Avogadro's number, or 6.02 × 10<sup>23</sup>. One mole of atoms is equal to 6.02 × 10<sup>23</sup> atoms." data-term-url="/en/glossary/view/mole/1515">moles</mark> 2) use the <mark class="term" data-term="Mole ratio" data-term-def="The proportional relationship (ratio) between any two compounds involved in a chemical reaction." data-term-url="/en/glossary/view/Mole+ratio/12125">mole ratio</mark> to determine how many moles of one reactant would be required to use up the other 3) calculate the amount of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> based on using up all the <mark class="term" data-term="limiting reactant" data-term-def="The reactant which, according to the mole ratio of the chemical equation, will be used up first and determines the amount&hellip;" data-term-url="/en/glossary/view/limiting+reactant/1570">limiting reactant</mark>.</p></p> <p>Step 1: Converting to moles<div class="figure"><figure> $$\text{150g } Ag \times \frac{(\text{1 mole})}{(\text{108g } Ag)} = \text{1.39 mol } Ag$$ </figure></div></p><p>and<div class="figure"><figure> $$\text{150g } HNO_3 \times \frac{({\text{1 mole}})}{(\text{63g }HNO_3)} = \text{2.38 mol }{HNO_3}$$ </figure></div><p>Step 2: Using the mole ratio to equate moles of Ag to moles of HNO<sub>3</sub></p></p><div class="figure"><figure> $$\frac{(\text{4 mol }HNO_3)}{(\text{3 mol }Ag)}$$ <p>Since silver is our expensive reactant, we want to use it all up. We can calculate how many moles of HNO<sub>3</sub> is required to react with the whole 1.39 mol of Ag, setting up the equation so that moles of HNO<sub>3</sub> cancel:</p></figure></div><div class="figure"><figure> $$\text{1.39 mol }Ag \times \frac{(\text{4 mol } HNO_3)}{(\text{3 mol } Ag)} = \text{1.85 mol }HNO_3 \text{ required}$$ <p>To use up all the, Ag, we need 1.85 moles of HNO<sub>3</sub>. Look at our calculations above. How much HNO<sub>3</sub> do we have? We have 2.38 moles - more than we need. In other words, if we put all of both reactants together, the silver will be used up first, and there will be HNO<sub>3</sub> left over. That makes silver the limiting reactant.</p></figure></div><p>This example shows the importance of converting to moles first. We started with the same mass of each reactant, 150 g. But mass doesn't tell us how many particles there are. That is what the unit of moles tells us. <p>Knowing that silver is the limiting reactant, we can go further and determine how many moles of AgNO<sub>3</sub> is produced from the 1.39 moles of Ag we are starting with. This time we use the mole ratio between Ag and AgNO<sub>3</sub>.</p><p>In the reaction:</p><div class="figure"><figure> $${3Ag} + {4HNO_3} \rightarrow {3AgNO_3} + {2H_2O} + {NO}$$ </figure></div><p>There are 3 moles of AgNO<sub>3</sub> produced for every 3 moles of Ag used. So:</p><div class="figure"><figure> $$\text{1.39 mol }Ag \times \frac{(\text{3 mol }AgNO_3)}{(\text{3 mol }Ag)} = \text{1.379 mol } AgNo_3 \text{ produced}$$ </figure></div></p><p>Calculations such as these are vital to our ability to manufacture and use chemicals efficiently, as well as to our ability to understand the impact of the <mark class="term" data-term="reaction" data-term-def="A chemical change when substances come into contact with each other." data-term-url="/en/glossary/view/reaction/8263">reactions</mark> that take place in our everyday world. For example, an engineer for a paint manufacturer must consider the <mark class="term" data-term="mole" data-term-def="An amount equal to Avogadro's number, or 6.02 × 10<sup>23</sup>. One mole of atoms is equal to 6.02 × 10<sup>23</sup> atoms." data-term-url="/en/glossary/view/mole/1515">mole</mark> <mark class="term" data-term="ratio" data-term-def="The relationship between two or more quantities; relative amounts of two or more values expressed as a proportion." data-term-url="/en/glossary/view/ratio/8556">ratios</mark> of different chemicals in the paint, which will determine the cost of producing that paint. On a grander <mark class="term" data-term="scale" data-term-def="An instrument for measuring heat energy or weight in which units are marked at intervals; a system for quantifying heat energy&hellip;" data-term-url="/en/glossary/view/scale/8536">scale</mark>, <mark class="term" data-term="Stoichiometry" data-term-def="The proportional relationship (ratio) between reactants and products in a chemical equation." data-term-url="/en/glossary/view/Stoichiometry/12126">stoichiometry</mark> plays a role in understanding <mark class="term" data-term="climate" data-term-def="Climate describes the average and patterns of a particular area’s weather over time. Climate includes such elements as temperature, precipitation, humidity,&hellip;" data-term-url="/en/glossary/view/climate/9334">climate</mark> change: if we know the quantities of different types of <mark class="term" data-term="fossil" data-term-def="The preserved impression or remains of an animal or plant whose living tissue has been replaced by minerals." data-term-url="/en/glossary/view/fossil/8558">fossil</mark> fuels burned in a year, we can determine how much CO<sub>2</sub> has been added to the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark>. From planning for s’mores to streamlining manufacturing and generating environmental <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark>, we can use stoichiometry to predict and plan the <mark class="term" data-term="outcome" data-term-def="Result." data-term-url="/en/glossary/view/outcome/8247">outcome</mark> of many chemical processes.</p></section> <section id="toc2_5"><h3>Summary</h3><p>Stoichiometry is the mathematics of chemistry. Starting with a balanced chemical equation, we make use of the proportional nature of <mark class="term" data-term="chemical reaction" data-term-def="A process in which atoms and molecules recombine by forming or breaking chemical bonds. Chemical reactions form new products that&hellip;" data-term-url="/en/glossary/view/chemical+reaction/1547">chemical reactions</mark> to calculate the amount of <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> needed at the start or predict the amount of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> that will be produced. While it may not seem all that “chemical,” <mark class="term" data-term="Stoichiometry" data-term-def="The proportional relationship (ratio) between reactants and products in a chemical equation." data-term-url="/en/glossary/view/Stoichiometry/12126">stoichiometry</mark> is a concept that underlies our ability to understand the impact and implications of many chemical processes. A bandage manufacturer may use <mark class="term" data-term="mole" data-term-def="An amount equal to Avogadro's number, or 6.02 × 10<sup>23</sup>. One mole of atoms is equal to 6.02 × 10<sup>23</sup> atoms." data-term-url="/en/glossary/view/mole/1515">mole</mark> <mark class="term" data-term="ratio" data-term-def="The relationship between two or more quantities; relative amounts of two or more values expressed as a proportion." data-term-url="/en/glossary/view/ratio/8556">ratios</mark> to determine how much silver is required (and therefor the cost) to treat a batch of bandages with silver nitrate. A fertilizer company might apply the concept of <mark class="term" data-term="limiting reactant" data-term-def="The reactant which, according to the mole ratio of the chemical equation, will be used up first and determines the amount&hellip;" data-term-url="/en/glossary/view/limiting+reactant/1570">limiting reactant</mark> to figure out how much product they can produce with a given amount of hydrogen <mark class="term" data-term="gas" data-term-def="The state of matter characterized by its non-condensed nature and ability to flow. Unlike liquids, molecules within a gas remain far&hellip;" data-term-url="/en/glossary/view/gas/8725">gas</mark>. And so on. Stoichiometry, <mark class="term" data-term="Mole ratio" data-term-def="The proportional relationship (ratio) between any two compounds involved in a chemical reaction." data-term-url="/en/glossary/view/Mole+ratio/12125">mole ratios</mark>, and limiting reactants are indispensable concepts for fully understanding any chemical <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark>.</p></section> <section id="toc2_6"><h3>Key Concepts</h3><ul class="bulleted"> <li><p>Stoichiometry uses the proportional nature of chemical equations to determine the amount of <mark class="term" data-term="reactant" data-term-def="The initial material that participates in a chemical reaction. Written on the left side of a chemical equation. Compare&hellip;" data-term-url="/en/glossary/view/reactant/1568">reactant</mark> needed to produce a given amount of <mark class="term" data-term="product" data-term-def="The material that is formed as a result of a chemical reaction. Written on the right side of a chemical equation.&hellip;" data-term-url="/en/glossary/view/product/1569">product</mark> or predict the amount that will be produced from a given amount of reactant.</p></li> <li><p>The <mark class="term" data-term="mole" data-term-def="An amount equal to Avogadro's number, or 6.02 × 10<sup>23</sup>. One mole of atoms is equal to 6.02 × 10<sup>23</sup> atoms." data-term-url="/en/glossary/view/mole/1515">mole</mark> <mark class="term" data-term="ratio" data-term-def="The relationship between two or more quantities; relative amounts of two or more values expressed as a proportion." data-term-url="/en/glossary/view/ratio/8556">ratio</mark> shows the proportion of one reactant or product in a <mark class="term" data-term="reaction" data-term-def="A chemical change when substances come into contact with each other." data-term-url="/en/glossary/view/reaction/8263">reaction</mark> to another, and is derived from the balanced chemical equation. While we may need to adjust the amount of reactants to yield more product, the ratio of reactants to products is always the same as the balanced reaction.</p></li> <li><p>The <mark class="term" data-term="limiting reactant" data-term-def="The reactant which, according to the mole ratio of the chemical equation, will be used up first and determines the amount&hellip;" data-term-url="/en/glossary/view/limiting+reactant/1570">limiting reactant</mark> is the chemical used up first in a reaction. it can be determined by comparing the number of moles of each reactant on hand and the <mark class="term" data-term="Mole ratio" data-term-def="The proportional relationship (ratio) between any two compounds involved in a chemical reaction." data-term-url="/en/glossary/view/Mole+ratio/12125">mole ratio</mark> between reactants and products in the balanced reaction.</p></li> </ul></section> <footer class="module__main__footer"> <hr class="border-color-dark"> <p class="citation"> <em> Robin Marks, M.A., Anthony Carpi, Ph.D. “Stoichiometry” Visionlearning Vol. CHE-4 (8), 2019. </em> </p>  <div class="title-list" id="refs" name="refs"> <p class="h6 title-list__title"> References </p> <ul class="title-list__list"> <li>The Haber-Bosch Reaction: An Early Chemical Impact On Sustainability</li> <li>https://pubs.acs.org/cen/coverstory/86/8633cover3box2.html</li> <li><p>Overview of the Haber-Bosch Process:</p></li> <li>https://www.thoughtco.com/overview-of-the-haber-bosch-process-1434563</li> </ul> </div> </footer> </div>    </article> </div> </div> </main>   <footer class="position-relative box-shadow-1 font-size-md" id="global-footer"> <h2 class="screen-reader-only">Page Footer</h2> <div class="back-to-top"> <div class="container wide"> <button class="button button--has-icon font-size-sm"> <span class="icon icon-arrow-up"></span> <span class="button__text">Back to top</span> </button> </div> </div> <div class="container wide padding-y-2"> <div class="grid grid--column-2--md grid--column-4--lg gap-4 grid--divider--fill-x"> <nav> <ul class="nav font-weight-bold"> <li> <a href="/en/library" title="Readings & quizzes"> Library </a> </li> <li> <a href="/en/glossary" title="Science terms"> Glossary </a> </li> <li> <a href="/en/classroom" title="Courses & bookmarks"> Classroom </a> </li> </ul> </nav> <nav> <ul class="nav"> <li><a href="/en/about">About</a></li> <li><a href="/en/help">Contact</a></li> <li><a href="/en/about/jobs">Jobs</a></li> <li><a href="/en/help/faq">FAQ</a></li> </ul> </nav> <div> <ul class="nav nav--horizontal margin-bottom-2"> <li> <a class="display-flex" href="https://www.nsf.gov" target="_blank" rel="noopener"> <img src="/images/sponsor-nsf.png" width="60" height="60" alt="US Education Department Logo" /> </a> </li> <li> <a class="display-flex" href="https://www.ed.gov/" target="_blank" rel="noopener"> <img src="/images/sponsor-doe.png" width="60" height="60" alt="US Education Department Logo" /> </a> </li> </ul> <p>Visionlearning is supported by the The National Science Foundation and the U.S. Department of Education. 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Stoichiometry | Chemistry | Visionlearning