The rate of a chemical reaction is the change in concentration over the change in time. Introduction The rate of a chemical reaction is the change in concentration over the change in time and is a metric of the "speed" at which a chemical reactions occurs and can be defined in terms of two observables: The Rate of Disappearance of Reactants \[-\dfrac{\Delta[Reactants]}{\Delta{t}} \nonumber \] Note this is negative because it measures the rate of disappearance of the reactants. The Rate of Formation of Products \[\dfrac{\Delta{[Products]}}{\Delta{t}} \nonumber \] This is the rate at which the products are formed. They both are linked via the balanced chemical reactions and can both be used to measure the reaction rate. Outside links http://en.Wikipedia.org/wiki/Reaction_rate www.chm.davidson.edu/vce/kinetics/ReactionRates.html(this website lets you play around with reaction rates and will help your understanding) goldbook.iupac.org/R05156.html www.youtube.com/watch?v=FfoQsZa8F1c YouTube video of a very fast exothermic reaction. References Petrucci et al. General Chemistry: Principles & Modern Applications, 9 th Edition . New Jersey: Prentice-Hall Inc., 2007. Connors, Kenneth. Chemical Kinetics: The Study of Reaction Rates in Solution . New York City: VCH Publishers, Inc., 1990. Problems Consider the reaction \(2A + B \longrightarrow C\). The concentration of [A] is 0.54321M and the rate of reaction is \(3.45 \times 10^{-6} M/s\). What Concentration will [A] be 3 minutes later? Consider the reaction \(A + B \longrightarrow C\). The rate of reaction is 1.23*10-4. [A] will go from a 0.4321 M to a 0.4444 M concentration in what length of time? Write the rate of the chemical reaction with respect to the variables for the given equation. \[2A+3B \rightarrow C+2D \nonumber \] True or False: The Average Rate and Instantaneous Rate are equal to each other. How is the rate of formation of a product related to the rates of the disappearance of reactants. Contributors Albert Law, Victoria Blanchard, Donald Le