Which from following gases of same mass exerts highest pressure at constant temperature?
Which from following gases of same mass exerts highest pressure at constant temperature?
$\mathrm{H}_2$
$\mathrm{N}_2$
$\mathrm{O}_2$
$\mathrm{Cl}_2$
Solution
Let us consider the mass of each gas $=1 \mathrm{~g}$ Order of molecular weight of the given gases: $\mathrm{H}_2 \lt \mathrm{N}_2 \lt \mathrm{O}_2 \lt \mathrm{Cl}_2$
$\therefore \quad$ The order of no. of moles: $\mathrm{H}_2\gt\mathrm{N}_2\gt\mathrm{O}_2\gt\mathrm{Cl}_2$
From ideal gas equation, $\mathrm{n} \propto \mathrm{V}$
$\therefore \quad$ Volume occupied by the gases is as follows:
$\mathrm{H}_2\gt\mathrm{N}_2\gt\mathrm{O}_2\gt\mathrm{Cl}_2$ At constant temperature, (Boyle's law)
$P \propto \frac{1}{V}$ Since volume occupied by $\mathrm{Cl}_2$ gas is the least,
$\therefore \quad \mathrm{Cl}_2$ gas exerts the highest pressure.