Question

A certain quantity of a gas occupies a volume of 0.1 litre when collected over water at ${27}^{0}C$ and pressure 1.67 atm. The same amount of gas occupied 0.14 litre at 1 atm, $7^{0}C$ in dry condition. Calculate the aqueous tension (in atm) at ${27}^{0}C$.

Answer 1

$P_{drygas}=P_{observed}-$ aqueous tension

now $P_{observed}=1.67$ atm

now, $\frac{P_1{V}_1}{T_1}=\frac{P_2{V}_2}{T_2}$

$\therefore$ Pressure of dry gas, $P_1=\frac{P_2{V}_2}{T_2}\times \frac{T_1}{V_1}$

$\Rightarrow P_1=\frac{1atm\times 0.14lit}{300K}\times \frac{280K}{0.1}$

$\Rightarrow P_1=1.31$ atm

$\therefore$ Aqueous tension $=P_{observed}-P_{drygas}=1.67-1.31=0.36$ atm