Question

Under certain conditions, the decomposition of ammonia on a metal surface gives the following data:

Determine the rate law, the rate constant, and the overall order for this reaction.

Short answer

The rate law for decomposition of ammonia is equal to the rate constant. The value of rate law and rate constant is \({\bf{1}}{\bf{.5 \times 1}}{{\bf{0}}^{{\bf{ - 6}}}}{\bf{mol/L/h}}\)

The overall order of the reaction is zero.

Step-by-step solution

Decomposition of ammonia on a metal surface

From the given table, it is clear that the rate of reaction is independent of the concentration of reactant which is the condition of zero order reaction.

Hence, decomposition of ammonia on a metal surface is a zero-order reaction. The gas is absorbed on the metal surface due to pressure.

Rate law and rate constant

The rate law for a zero-order reaction is as follows:

\({\bf{Rate = k}}\)

Where k is a rate constant.

So, for decomposition of ammonia rate law will be equal the rate constant and does not depend on the concentration of reactant.

Value of rate constant\({\bf{k = 1}}{\bf{.5 \times 1}}{{\bf{0}}^{{\bf{ - 6}}}}{\bf{mol/L/h}}\)

Rate law\({\bf{ = k = 1}}{\bf{.5 \times 1}}{{\bf{0}}^{{\bf{ - 6}}}}{\bf{mol/L/h}}\)

Hence, the overall rate of reaction will be zero.