Question

Calculate the mass in mole of $C{O}_2$ that will dissolve in enough water to form $900mL$ of solution at ${20}^{\circ }C$ if the partial pressure of $C{O}_2$ is $1atm$. $K_H$ for $C{O}_2$ is $2.3\times {10}^{-2}mol/litre-atm$.

• A. $0.0401mole$
• B. $0.0301mole$
• C. $0.0217mole$
• D. $0.0207mole$

Answer 1

Answer: (D)

$0.0207mole$

According to Henry's law, $S=KP$
S is the solubility in moles per litre
K is the henry's law constant
P is the pressure in atm.
Substitute values in the above expression.
$S=2.3\times {10}^{-2}mol/litreat{m}^{-1}\times 1atm=2.3\times {10}^{-2}M$
Thus 1 L of solution contains $2.3\times {10}^{-2}$ moles of carbon dioxide.
900 ml of solution will contain $2.3\times {10}^{-2}\times \frac{900}{1000}=0.0207$ mole.