**Problem : **

Given the below initial rate data, determine the rate law and
rate constant for the
following reaction:

Using the method of initial rates, we take the ratio of rates between
reactions 2 and 1 to determine the
order of the reaction in permanganate.

By taking the ratios of the rates of experiments 3 and 1 we can obtain the
order of the reaction in
chlorite.

Finally, by taking the ratios of the rates of experiments 4 and 1 we can
obtain the order of the reaction
in H^{+}.

Now that we know the order of the reaction in permanganate is 2, chlorite
is 1, and H^{+} is 1/2, we can use the rate and concentration data in experiment 1 to calculate the rate constant.

**Problem : **

What is the half-life of a zero order reaction?

Starting with the integrated rate law for a zero order reaction, we
rearrange the variables so we can
make the substitution that [A] / [A]_{o} = 0.5 when t =
t_{1/2}, we derive the
following equation:

**Problem : **

Given the following rate data concerning the decomposition
of sodium azide into
nitrogen gas, determine its rate law including the rate constant with the
appropriate units. This
reaction is used to produce the gas needed to inflate airbags.

The graph of ln [HN_{3}] versus time is linear:

That means the reaction is a first order decay process with a rate law rate
= k [NaN_{3}].
The value of k is the negative of the value of the slope, so k = 0.056
s^{-1}.