3 moles of P and 2 moles of Q are mixed, what will be their total vapour pressure in the solution if their partial vapour pressures are 80 and 60 torr respectively?

Question

3 moles of P and 2 moles of Q are mixed, what will be their total vapour pressure in the solution if their partial vapour pressures are 80 and 60 torr respectively? (A) 80 torr (B) 140 torr (C) 72 torr (D) 70 torr

Tardigrade Admin · Accepted Answer

Mole fraction of P = (3/3 + 2) = 0.6 Mole fraction of Q = (2/3+2) =0.4 Ptotal = Pp +PQ = P°pxp + P°QxQ = 80 × 0.6 + 60 × 0.4 = 72 torr

Q. $3$ moles of $P$ and $2$ moles of $Q$ are mixed, what will be their total vapour pressure in the solution if their partial vapour pressures are $80$ and $60 t orr$ respectively?

$80 t orr$

$140 t orr$

$72 t orr$

$70 t orr$

Mole fraction of $P = \frac{3}{3 + 2} = 0.6$
Mole fraction of $Q = \frac{2}{3 + 2} = 0.4$
$P_{t o t a l} = P_{p} + P_{Q} = P_{p}^{\circ} x_{p} + P_{Q}^{\circ} x_{Q}$
$= 80 \times 0.6 + 60 \times 0.4 = 72 t orr$

Q. 3 moles of P and 2 moles of Q are mixed, what will be their total vapour pressure in the solution if their partial vapour pressures are 80 and 60torr respectively?

80torr

140torr

72torr

70torr