NEETChemistry-Solutions

NEET Chemistry Raoult's Law MCQ Question

Type: MCQ-numerical-Hard-Class 12

Vapour pressure of benzene at 30°C is 121.8 mm. When 15 g of a non volatile solute is dissolved in 250 g of benzene, its vapour pressure decreased to 120.2 mm. The molecular weight of the solute (Mo. wt. of solvent = 78)

A

356.2

B

456.8

C

530.1

D

656.7

Correct Answer

Option A

Detailed Explanation

Using Raoult's law, the decrease in vapor pressure is used to calculate the molar mass of the solute. The calculation gives a molar mass of approximately 356.2 g/mol.

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