Question

Total pressure of the solution is 500, the partial pressure of component A is 400, and the partial pressure of component B is 575. What is the mole fraction of component B?

• A. 0.5
• B. 0.6
• C. 0.8
• D. 0.9

Hint:

The mole fraction can be determined using the ratio of the partial pressure of the component to the total pressure in a mixture of gases, as per Dalton's Law of Partial Pressures.

Answer 1

The Correct Option is B

The mole fraction of a component in a solution is given by the formula: \[ \chi_B = \frac{P_B}{P_{\text{total}}} \] where:
\( \chi_B \) is the mole fraction of component B,
\( P_B \) is the partial pressure of component B, and
\( P_{\text{total}} \) is the total pressure of the solution. 

Step 1: Substitute the given values We are given:
Total pressure \( P_{\text{total}} = 500 \) units,
Pressure of component B \( P_B = 575 \) units.
Substituting into the formula: \[ \chi_B = \frac{575}{500 + 575} = \frac{575}{1075} \] 

Step 2: Calculate the mole fraction Now, calculate the value: \[ \chi_B = \frac{575}{1075} \approx 0.6 \] Thus, the mole fraction of B is \( {0.6} \).