Question

The vapour pressure of a solution (P) and the vapour pressure of the solvent (P$^\circ$) are related to each other as ($x_1$ is the mole fraction of solvent)

• A. P = P$^\circ$ $x_2$
• B. $P = P^\circ x_1$
• C. P$^\circ$ =$Px_1$
• D. P$^\circ$ = $Px_2.$

Answer 1

Answer: (B)

$P = P^\circ x_1$

Answer 2

Vapour pressure of solution $(P)$ = Vapour pressure of the solvent in solution = Mole fraction of the solvent $\times$ V. P of pure solvent $P = x_1 \times P_0 = P^0 x_1$