Relative Lowering of Vapour Pressure
Important Questions on Relative Lowering of Vapour Pressure
When a certain amount of solid is dissolved in of water at 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 . The number of moles of solute added is

of at and is passed through of solution. The non-volatile solute produced is dissolved in of water. The lowering of vapour pressure of solution (assuming the solution is dilute) ( of ) is of the value of is (Integer answer)

A set of solutions is prepared using of water as a solvent and of different non-volatile solutes and . The relative lowering of vapour pressure in the presence of these solutes are in the order [Given, molar mass of ]

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:

At room temperature, a dilute solution of urea is prepared by dissolving of urea in of water. If the vapour pressure of pure water at this temperature is , lowering of vapour pressure will be:
(molar mass of urea )

The mass of a non-volatile, non-electrolyte solute (molar mass ) needed to be dissolved in octane to reduce its vapour pressure by , is:

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

The vapour pressure of acetone at is . When of a non-volatile substance was dissolved in of acetone at , its vapour pressure was . The molar mass of the substance is:

