Liquids A and B form an ideal solution in the entire composition range. At 350K, the vapour pressures of pure A and B are `9 xx 10^3` Pa and `16 xx 10^3` Pa, respectively. The composition of the vapour in equilibrium with a solution containing 30 mole percent of A at this temperature is:

Options

A. `X_A = 0.2 , X_B = 0.8`
B. `X_A = 0.8 , X_B = 0.2`
C. `X_A = 0.28 , X_B = 0.72`
D. `X_A = 0.72 , X_B = 0.28`

Explanation

To find the composition of the vapor in equilibrium with a solution containing 30 mole percent of A at 350 K, we can follow these steps:

### Step 1: Identify the given data
- Vapor pressure of pure A, \( P^0_A = 9 \times 10^3 \) Pa
- Vapor pressure of pure B, \( P^0_B = 16 \times 10^3 \) Pa
- Mole fraction of A in the solution, \( x_A = 0.3 \) (30 mole percent)
- Mole fraction of B in the solution, \( x_B = 1 - x_A = 0.7 \)

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