At STP 10 grams of CO can be dissolved in 3 L of water. Calculate the solubility of carbon monoxide at 200kPa.
moles CO = 10 g x 1mol 28g = 0.357 moles in 3 L = 0.119 mol/L at STP
P1/n1 = P2/n2
101.325 kPa/0.119 = 200 kPa/n2
n2 = 0.235 moles/L = 0.235mol x 28g/mol = 6.6g/L (assuming no change in temp)
Answer : The solubility of carbon monoxide gas at pressure 200 kPa is, 6.579 g/L
Explanation :
According top the Henry's Law, the solubility of a gas in a liquid is directly proportional to the pressure of the gas.
\(S\propto P\)
or,
\(\frac{S_1}{S_2}=\frac{P_1}{P_2}\)
where,
\(S_1\) = initial solubility of gas = \(\frac{10g}{3L}\)
\(S_2\) = final solubility of gas = ?
\(P_1\) = initial pressure of gas = 101.325 kPa (at STP)
\(P_2\) = final pressure of gas = 200 kPa
Now put all the given values in the above formula, we get the final solubility of the gas.
\(\frac{\frac{10g}{3L}}{S_2}=\frac{101.325kPa}{200kPa}\)
\(S_2=6.579g/L\)
Therefore, the solubility of carbon monoxide gas at pressure 200 kPa is, 6.579 g/L