Chapter 20, Problem 20.92QP

Interpretation Introduction

Interpretation: The amount of ${\text{Zn}}^{64}$ produce should be determined after 18.4h.

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 & unstability of atoms or radioactive decay.
• For determination of first order rate constant K in half –life period we use

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

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

Formula:

First order rate constant: $\text{K=}\frac{\text{0}\text{.693}}{{\text{t}}_{\text{1/2}}}$

Age calculation:

$\text{ln}\frac{{\text{N}}_{\text{t}}}{{\text{N}}_{\text{0}}}\text{=-kt}$

To find: The half-life