Question

The Henry's law constant for oxygen is $1.3 \times 10^{-3}\ \text{mol dm}^{-3}\text{atm}^{-1}$. If partial pressure of oxygen is $0.46$ atmosphere, what is the concentration of dissolved oxygen at $25^\circ$C and 1 atm pressure?

• A. $5.98 \times 10^{-4}\ \text{mol dm}^{-3}$
• B. $3.53 \times 10^{-4}\ \text{mol dm}^{-3}$
• C. $5.98\ \text{mol dm}^{-3}$
• D. $2.82 \times 10^{-3}\ \text{mol dm}^{-3}$

Hint:

Henry’s law applies best to dilute solutions of gases at low pressure.

Answer 1

The Correct Option is A

Step 1: Statement of Henry's law.
According to Henry's law, the concentration of a gas dissolved in a liquid is directly proportional to its partial pressure.
\[ C = k_H \times P \]
Step 2: Substitution of given values.
\[ C = (1.3 \times 10^{-3}) \times 0.46 \]
Step 3: Calculation.
\[ C = 5.98 \times 10^{-4}\ \text{mol dm}^{-3} \]
Step 4: Conclusion.
Therefore, the concentration of dissolved oxygen is $5.98 \times 10^{-4}\ \text{mol dm}^{-3}$.