Question

Relative lowering in vapour pressure depends on _______.

Options

• nature of solute and solvent

• nature of solvent

• mole fraction of solute

• nature of solute

Answer 1

Relative lowering in vapour pressure depends on mole fraction of solute.

Explanation:

Relative lowering in vapour pressure,

`(Delta"P")/"P"^0 = x_2 = "n"_2/("n"_1 + "n"_2) = ("P"^0 - "P")/"P"^0`

Where, P⁰ = vapour pressure of pure solvent, P = vapour pressure of solution,

x₂ = mole fraction of solute, n₂ = number of moles of solute,

n₁ = number of moles of solvent.