Consider the following reaction and experimental data:

A + B → AB

Trial |
[A] (mol/L) |
[B] (mol/L) |
Rate
(molL |

1 |
0.66 |
0.55 |
0.096 |

2 |
0.33 |
0.55 |
0.012 |

3 |
0.33 |
1.10 |
0.024 |

What is the rate constant of the reaction?

First write out the rate law using the experimental data:

(Trial 1)

(Trial 2)

(Trial 3)

To find a, divide the equation from trial 1 by the equation from trial 2 (when [B] is constant):

To find b, divide the equation from trial 3 by the equation from trial 2 (when [A] is constant):

Now use any equation, and plug in the experimental values:

Using trial 1

Pay attention to the units of the rate constant: