Question

Define vapour pressure. Why does the addition ofa non-volatile solute to a volatile solvent lower its vapour pressure?

Answer 1

Answer:

Vapour pressure of a liquid is the pressure exerted by the vapour in equilibrium with the liquid at a particular temperature.

when a nonvolatile solute is added the escaping tendency of the solvent molecules decreases simce the surface is covered with both solute and solvent as a result the vapour pressure also decreases.

Hope it helps you

Answer 2

Answer:

Explanation:

the pressure of a vapour in contact with its liquid or solid form.

If you add a nonvolatile solute to solvent such as water, you decrease the tendency for water molecules to evaporate into the gas phase. ... As a result, fewer molecules change from the liquid to the gas phase, thus reducing the vapor pressure.