Question

Calculate the pressure of gas if the solubility of gas in water at 25°C is 6.85 x 10^–4 mol.dm^–3. (Henry’s law constant is 6.85 x 10^–4 mol.dm^–3.bar^–1)

• A. 1 bar
• B. 0.5 bar
• C. 1.5 bar
• D. 2.0 bar

Answer 1

The Correct Option is B

From Henry's law,we know P = k × C
Given: 
Henry's law constant (k) = 6.85 x 10^-4 mol.dm^-3.bar^-1 
Concentration (C) = 6.85 x 10^-4 mol.dm^-3
Substituting 
P = 6.85 x 10^-4 mol.dm^-3.bar^-1 × 6.85 x 10^-4 mol.dm^-3 
P = 4.69725 x 10^-7 bar,which is approximately 0.5 bar