Chapter 20, Problem 103AP

Interpretation Introduction

Interpretation:

The volume of Helium (He) gas collected at STP is to be calculated.

Concept introduction:

The amount of a particular radioactive isotope left after time t is given as:

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

Here, $k$

is the rate constant for the radioactive decay, ${\text{N}}_{\text{t}}$ is the amount of it left after time t, and ${\text{N}}_{\text{0}}$ is the initial amount of the sample.

Nearly all radioactive decays are of first order and the rate constant is given as:

$k\text{ = }\frac{0.693}{t_{1/2}}$

Here, $t_{1/2}$

is the half -life of the radioactive substance.

The volume of the ideal gas is calculated using the ideal gas equation as:

$\text{V = }\frac{\text{nRT}}{\text{P}}$

Here, V is the volume, P is the pressure, T is the temperature, and n is the number of moles of the gas.