Question

Henry's constant (in $kbar$) for four gases $\alpha, \beta, \gamma$ and $\delta$ in water at $298\, K$ is given below :

(density of water $=10^3 \,kg \,m ^{-3}$ at $298\, K$ )
This table implies that :

• A. $\alpha$ has the highest solubility in water at a given pressure
• B. solubility of $\gamma$ at $308 \,K$ is lower than at $298\, K$
• C. The pressure of a $55.5$ molal solution of $\gamma$ is $1 \,bar$
• D. The pressure of a $55.5$ molal solution of $\delta$ is $250$ bar

Answer 1

Answer: (D)

(a) From Henry's law $p=K_{ H }(x)$
Higher the value of $K_{ H }$ smaller will be the solubility of the gas, so $\gamma$ is more soluble.
(b) Though solubility of gases will decrease with increase in temperature but this conclusion can not be drawn from the given table.
(c) For $\gamma$
$(p)_\gamma=\left(K_{ H }\right)_\gamma \cdot(x)_\gamma=2 \times 10^{-5}\left[\frac{55.5}{55.5+\frac{1000}{18}}\right]$
$=10^{-5} k \text { bar }=10^{-2} bar$
(d) For $\delta \Rightarrow$
$ p_\delta=\left(K_{ H }\right)_\delta \cdot(x)_\delta=0.5\left[\frac{55.5}{55.5+\frac{1000}{18}}\right] $
$= 0.5 \times 0.5=0.25 \,k \text { bar }=250\, bar .$