Reaction rate

<p>The reaction rate or rate of reaction is the speed at which a <a href="/facts/Chemical_reaction/GpqWlKrz">chemical reaction</a> takes place, defined as proportional to the increase in the <a href="/facts/Concentration/wqBmz5od">concentration</a> of a <a href="/facts/Product_(chemistry)/8uCoDUdv">product</a> per unit time and to the decrease in the concentration of a <a href="/facts/Reactant/c3GLInCu">reactant</a> per unit time.  Reaction rates can vary dramatically. For example, the <a href="/facts/Rusting/sajUmaz8">oxidative rusting</a> of <a href="/facts/Iron/QK1JYy8E">iron</a> under <a href="/facts/Earth%2527s_atmosphere/FV97Am25">Earth's atmosphere</a> is a slow reaction that can take many years, but the combustion of <a href="/facts/Cellulose/wYPafTU0">cellulose</a> in a fire is a reaction that takes place in fractions of a second. For most reactions, the rate decreases as the reaction proceeds. A reaction's rate can be determined by measuring the changes in concentration over time.
</p><p><a href="/facts/Chemical_kinetics/D8vyX4aE">Chemical kinetics</a> is the part of <a href="/facts/Physical_chemistry/WqwnJjRM">physical chemistry</a> that concerns how rates of chemical reactions are measured and predicted, and how reaction-rate data can be used to deduce probable <a href="/facts/Reaction_mechanism/9lanyVuy">reaction mechanisms</a>. The concepts of chemical kinetics are applied in many disciplines, such as <a href="/facts/Chemical_engineering/Fb64amQf">chemical engineering</a>, <a href="/facts/Enzymology/DSI1Fh7y">enzymology</a> and <a href="/facts/Environmental_engineering/He7fly74">environmental engineering</a>.
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Reaction rate open-in-new

Reaction rate