Question

Calculate the concentration of dissolved gas in water at $25^\circ\text{C}$ if partial pressure of gas at same temperature is 0.15 atm . $[\text{K}_\text{H} = 0.15 \text{ moldm}^{-3} \text{atm}^{-1}]$}

• A. 0.0261 M
• B. 0.0182 M
• C. 0.0293 M
• D. 0.0225 M

Hint:

$S = K_H P$. It's a simple multiplication of the constant and the pressure.

Answer 1

The Correct Option is D

Step 1: Concept
Henry's Law states that the solubility ($S$) of a gas in a liquid is directly proportional to its partial pressure ($P$): $S = K_H \times P$.

Step 2: Meaning
Solubility $S$ is expressed in concentration ($M$ or $\text{mol dm}^{-3}$).

Step 3: Analysis
Given: $K_H = 0.15 \text{ moldm}^{-3}\text{atm}^{-1}$, $P = 0.15 \text{ atm}$. $S = 0.15 \times 0.15 = 0.0225 \text{ mol dm}^{-3}$.

Step 4: Conclusion
The concentration of the dissolved gas is 0.0225 M. Final Answer: (D)