MODEL PAPER 10 — Chemistry STD 12 Science — Question

i. Reverse osmosis (direction of osmosis is reversed) occurs i.e. net flow of the solvent is from solution to solvent. Hence greater pressure is applied to the solvent molecules from the solution side would move into the pure solvent through a semipermeable membrane.
ii. When acetone is added to the ethanol, molecules of acetone get in between the molecules of ethanol and break some of the hydrogen bond, which weakens the intermolecular attractive forces resulting in an increase in vapor pressure of the mixture than ethanol in a pure state.