Relative Lowering of Vapour Pressure

Author:Embibe Experts
JEE Main
IMPORTANT

Important Questions on Relative Lowering of Vapour Pressure

HARD
IMPORTANT

When a certain amount of solid A is dissolved in 100 g of water at 25 °C to make a dilute solution, the vapour pressure of the solution is reduced to one-half of that of pure water. The vapour pressure of pure water is 23.76mmHg. The number of moles of solute A added is

HARD
IMPORTANT

224 mL of SO2(g) at 298 K and 1 atm is passed through 100 mL of 0.1 M NaOH solution. The non-volatile solute produced is dissolved in 36 g of water. The lowering of vapour pressure of solution (assuming the solution is dilute) (P°H2O=24 mm of Hg) is x×10-2 mm of Hg the value of x is                (Integer answer)

EASY
IMPORTANT

A set of solutions is prepared using 180 g of water as a solvent and 10 g of different non-volatile solutes A, B and C. The relative lowering of vapour pressure in the presence of these solutes are in the order [Given, molar mass of A=100 g mol-1 ; B=200 g mol-1 ; C=10,000 g mol-1]

EASY
IMPORTANT

Two open beakers one containing a solvent and the other containing a mixture of that solvent with a non volatile solute are together sealed in a container. Over time:

MEDIUM
IMPORTANT

At room temperature, a dilute solution of urea is prepared by dissolving 0.60 g of urea in 360 g of water. If the vapour pressure of pure water at this temperature is 35 mm Hg , lowering of vapour pressure will be:
(molar mass of urea =60 g mol-1 )

EASY
IMPORTANT

The mass of a non-volatile, non-electrolyte solute (molar mass = 50 g mol-1) needed to be dissolved in 114 g octane to reduce its vapour pressure by 75%, is:

MEDIUM
IMPORTANT

18 g glucose C6H12O6 is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is:

MEDIUM
IMPORTANT

The vapour pressure of acetone at 20oC is 185 torr. When 1.2 g of a non-volatile substance was dissolved in 100 g of acetone at 20oC , its vapour pressure was 183 torr. The molar mass (g mol-1) of the substance is: