Chapter 20, Problem 20.27QP

Interpretation Introduction

Interpretation: The number of moles of A, B, C and D left after 30 days should be calculated.

Concept Introduction:

• Half-life period: The time required to the reduce to half of its original value.
• This is denoted by: ${\text{t}}_{\text{1/2}}$
• This term is popularly use in nuclear chemistry, to describe the stability & instability of atoms or radioactive decay.
• For determination of first order rate constant K in half –life period we use

  $\text{K=}\frac{\text{0}\text{.693}}{{\text{t}}_{\text{1/2}}}$

• The half-life in first order does not depend upon the initial concentration.

Given:

A, B, & C are radioactive in nature with the half-live of 4.50s, 15dyas and 1.00s respectively.

D is nonradioactive in nature.