Chapter 19, Problem 19.114MP

Interpretation Introduction

Interpretation:

Since the pressure is due to the helium gas or the alpha particles, which depends on the mass of helium formed.

Concept introduction:

For half-life we can determine the decay constant as

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

1^st order reaction

$\lambda =\frac{1}{t_{}}\ln \left(\frac{A_o}{A_t}\right)$

From the ideal gas equation

$PV=nRT$

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

Given:

$Po$ emits $\alpha$ radiation
Half-life of $Po$ =138 days
Initial mass of a $Po$ , A_o = 0.700mg
Volume of the flask = 250.0 mL
Temperature= 20^oC or 293 K
Time duration = 365 days

To determine:

The pressure inside the flask in mm Hg at 20^oC after 365 days if all the $\alpha$ particles emitted had become helium atoms.