Chapter 20, Problem 20.93QP

Interpretation Introduction

Interpretation:

Molar mass of the isotope should be calculated.

Concept introduction:

• $\text{molar}\text{mass}\text{=}\frac{\text{mass}\text{of}\text{substance}}{\text{mol}\text{of}\text{substance}}$
• Half-life of radioactive decay is the time required for a radioactive sample to decay to one half of the atomic nucleus.

$\begin{array}{c}{\text{t}}_{\text{1/2}}\text{=}\frac{\text{0}\text{.693}}{\text{k}}\\ \text{where,}{\text{t}}_{\text{1/2}}\text{=}\text{half-life}\text{of reaction}\\ \text{k}\text{=}\text{Rate constant}\end{array}$

• $\begin{array}{c}\text{rate}\text{of}\text{decay}\text{=}\text{kN}\\ \text{where,}\text{N=}\text{Number of radioactive nuclei}\end{array}$

To determine: Molar mass of the isotope