Question

The vapour pressure of CCl₄ at 30°C is 143 mm of Hg.0.5 gm of a nonvolatile non electrolyte substance with molar mass 65 is dissolved in 100 ml of CCl₄. What will be the vapour pressure of the solution. Density of CCl₄ at 30°C = 1.58 gm per cc. 

Answer 1

Vapour pressure of pure solvent, P°=143 mm of Hg. 

Vapour pressure of solution, p = ? 

Weight of solute, W₂ = 0.5 gm 

Mol. wt of solute, M₂ = 65

Mol. wt of solvent (CCl₄), M₁ = 154

Weight of solvent, W₁ = 100x1.58 =158 gm

(mass = density x volume)