Chapter 11, Problem 39QRT

(a)

Interpretation Introduction

Interpretation:

The concentration of the reactant $60s$ after initiation of the reaction has to be calculated.

Concept Introduction:

The integrated rate equation for first order reaction is given below.

  $\lambda t=\ln \frac{{\left[A\right]}_o}{{\left[A\right]}_t}$

Where,

    $\lambda =$ rate constant/ decay constant

    $t=$ time taken to change the concentration from ${\left[A\right]}_{o}to{\left[A\right]}_t$

    ${\left[A\right]}_o=$ initial concentration of $A$

    ${\left[A\right]}_t=$ final concentration $A$

Half-life of a first order reaction can be calculated using following equation.

  $t_{\frac{1}{2}}=\frac{0.693}{\lambda }$

(b)

Interpretation Introduction

Interpretation:

The time taken for the concentration of the reactant to drop to one-eighth its initial value has to be calculated.

Concept Introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

The time taken for the concentration of the reactant to drop to $0.040mol{L}^{-1}$ has to be calculated.

Concept Introduction:

Refer to part (a).