CAS CH 110 Lecture Notes - Lecture 29: Rate Equation
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Summary: using initial rates experimental data we can find a rate law expression, rate = k [a]a[b]b the orders a, b, and constant, k. Now, we extend our initial rates ideas into a way to predict concentrations; this will require calculus. Integrating the three rate laws will give us future concentrations. Start by using our first order rate expression, rate = k[a]. Our goal is to express the rate as [a] changes over time. Rate of disappearance of a: - d[a] /dt = k[a] Divide both sides by [a] to keep the [a]"s together and move the dt so we can integrate the expression. Now we integrate for concentration and for time. The half-life, t1/2 , is the time needed for its concentration to fall to onehalf of its initial value. The higher the value of k, the more rapid the consump-tion of a reactant.