Chapter 12, Problem 99CWP

Interpretation Introduction

Interpretation:

The true statement has to be identified from the given set of statements.

Concept introduction:

Rate constant: Rate law is the equation that relates the concentration of the reactant to the rate of the reaction.  Consider the reaction where the reactant $\text{A}$ and $\text{B}$ is giving product $\text{P}$.

$\text{A+B}\to \text{P}$

The rate law of the reaction can be expressed as given below.

$\begin{array}{l}\text{Rate}\infty \left[\text{A}\right]\left[\text{B}\right]\\ \text{or}\\ \text{Rate}\text{=k}\left[\text{A}\right]\left[\text{B}\right]\end{array}$

The proportionality sign is changed by a constant $\text{k}$, which is the rate constant of the reaction.  Rate constant depends upon the temperature, pressure and activation energy.

Half- life $\left({\text{t}}_{\frac{\text{1}}{\text{2}}}\right)$: It is the time taken to reduce the concentration of the reactant to half of its initial value.  Half-life of a second order reaction is calculated using the equation given below.

${\text{t}}_{\frac{\text{1}}{\text{2}}}\text{=}\frac{\text{1}}{\text{k}{\left[\text{AB}\right]}_{\text{°}}}$

Where,

$\text{k}$ is the rate constant of the reaction.

${\left[\text{AB}\right]}_{\text{°}}$ is the initial concentration of the reactant.