Question

What percentage of a sample of nitrogen must be allowed to escape, if its temperature, pressure and volume are changed from ${220}^{\circ }\text{C},3.0$ atm and $1.65\text{L}$ to ${110}^{\circ }\text{C}$, 0.7 atm and 1.0 L respectively?

Answer 1

Applying the formula, $m$ (mass of the gas)
$=\frac{PV\times M}{RT}$, under both the conditions,
Mass of gas before escaping $==\frac{3.0\times 1.65\times 28}{0.0821\times 493}=3.42\text{g}$
Mass of gas after escaping $=\frac{0.7\times 1.0\times 28}{0.0821\times 383}=0.62\text{g}$
Percentage of nitrogen allowed to escape $=\frac{(3.42-0.62)}{3.42}\times 100=81.87$