The vapour pressure of a solution having 2 0 g of solute X (molar atomic mass = 32 g mol - Chemistry - Solutions

Question

The vapour pressure of a solution having 2 0 g of solute X (molar
atomic mass = 32 g mol–1) in 100 g of
CS2 (vapour pressure = 854 torr) is 848 9 torr The
molecular formula of the solute is:-

(1) X
(2) X2
(3) X4
(4) X8
Kindly answer sir/mam

Geetha · Accepted Answer

According to lowering of vapour pressure,P0-PP0 = W2W1 × M1M2P0 - vapour pressure of pure solvent = 854 torrP -vapour pressure of solution = 848
9 torr
W2 - weight of the solute = 2 gW1 - weight of the solvent = 100 gM2 - molecular mass of the solute = ?M1 - molecular mass of the solvent CS2= 12 + 2 × 32 = 12 + 64 = 76 g854 - 848
9854 = 2100 × 76M2M2 = 2 × 76 × 854100 × (854 - 848
9) = 254
5 gMolecular weight of the solute  = X × nWhere X = atomic mass = 32X × n = 254
5n = 254 5X = 254 532 =7
95Thus the formula of the solute = X8

The vapour pressure of a solution having 2.0 g of solute X (molar atomic mass = 32 g mol–1) in 100 g of CS2 (vapour pressure = 854 torr) is 848.9 torr. The molecular formula of the solute is:- (1) X (2) X2 (3) X4 (4) X8 Kindly answer sir/mam.

The vapour pressure of a solution having 2.0 g of solute X (molar atomic mass = 32 g mol^–1) in 100 g of CS₂ (vapour pressure = 854 torr) is 848.9 torr. The molecular formula of the solute is:-

(1) X
(2) X₂
(3) X₄
(4) X_{8

Kindly answer sir/mam.}