5.8 g of non - volatile, non - electrolyte solute was dissolved in 100 g of carbon disuiphide (CS_(2)). The vapour pressure of the solution was found to be 190 mm of Hg. Calculate molar mass of the solute. Given : Vapour of pure CS_(2) is 195 mm of Hg and molar mass of CS_(2) is 76g//mol.

5.8 g of non - volatile, non - electrolyte solute was dissolved in 100

1.	5.8 g of non - volatile, non - electrolyte solute was dissolved in 100 g of carbon disuiphide (CS_(2)). The vapour pressure of the solution was found to be 190 mm of Hg. Calculate molar mass of the solute. Given : Vapour of pure CS_(2) is 195 mm of Hg and molar mass of CS_(2) is 76g//mol.
Answer» Solution :MASS of SOLUTE`(W_(B))=5.8 g`. Mass of solvent i.e., `CS_(2)` is `(W_(A))=100g` Vapour pressure of solution `(RHO)=190` mm of Hg. Vapour pressure of pure solvent `(P_(A))=195` mm of Hg Molar mass of pure solvent`CS_(2)(M_(A))=76 gmol^(-1)`. `M_(B)(p_(A)-p)/(p_(A)^(0))=(W_(B)M_(A))/(M_(B)W_(A))` `(195-190)/(195)=(5.8xx76)/(M_(B)xx100)` `(5)/(195)=(5.8xx76)/(M_(B)xx100)` `M_(B)=(5.8xx76xx195)/(5xx100)=1719 gmol^(-1)`