Question

Q1.
Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and
that of toluene is 22 torr. The parial vapour pressure of benzene at 20°C for a solution containing 78g of
benzene and 46g of toluene in torr is
(A) 50
(B) 25
(C) 37.5
(D) 53.5
​

Answer 1

Answer:

Option (A) 50 torr

Step-by-step explanation:

PB =P°BXB

=> PB = 75 torr

=> XB = 78/78/(78/78)+(46/92)

=> XB = 1/1+0.5 = 1/1.5

=> PB = 75 x 1/1.5 = 50 torr

(Refer attachment)

Extra information :-

•This is based on raoults law

=> statement

•The partial pressure of a volatile component of a solution is directly proportional to its mile faction in solution at any temperature.