Question

If $CO _{2}$ gas having a partial pressure of $1.67$ bar is bubbled through $1\, L$ water at $298\, K$, the amount of $CO _{2}$ dissolved in water in $g\, L ^{-1}$ is approximately. (Henry's law constant of $CO _{2}$ is $1.67 k$ bar at $298 K$ )

• A. 24.42
• B. 12.21
• C. 2.44
• D. 1.22

Answer 1

Answer: (C)

Let $p_{A}$ be the partial pressure of $CO _{2}$ and $\chi_{A}$ be its mole

$p_{A} =K_{ H } \chi_{A}$ (Henry's law)

$1.67 $ bar $=1.67\, k $ bar $\times \chi_{A} $

(where,$ x_{A} =0.001)$

or $\frac{n_{A}}{n_{B}}=0.001$

$[\because$ Number of moles of water $=55$ ]

$n_{A} =0.001 \times 55.55$

$n_{A} =0.056$

$n=\frac{\text { Given mass}(m)}{\text { Molecular mass }(M)}=0.056 $

$\therefore m=0.056 \times 44=2.44\, g$

Thus, $2.44 g$ of $CO _{2}$ is dissolved in $1 \,L$ water at $298\ K$