Question

A decomposition reaction, with a rate that is observed to slow down as the reaction proceeds, has a half-life that does not depend on the initial concentration of the reactant. Which statement is most likely true for this reaction?
O A doubling of the initial concentration of the reactant results in a quadrupling of the rate.
O A plot of the natural log of the concentration of the reactant as a function of time is linear.
O The half-life of the reaction increases as the initial concentration increases.

Answer 1

Answer: A plot of the natural log of the concentration of the reactant as a function of time is linear.

Explanation:

Since it was explicitly stated in the question that the half life is independent of the initial concentration of the reactant then the third option must necessarily be false. Also, the plot of the natural logarithm of the concentration of reactant against time for a first order reaction is linear. In a first order reaction, the half life is independent of the initial concentration of the reactant. Hence the answer.