Question

Wilted flowers revive when placed in fresh water.

1. Identify and dene the phenomenon.

2. Mixing of acetone and CHCl₃ results in a reduction in volume. What type of deviation from Raoult’s law is observed here? Give reason.

3. Benzoic acid dissolved in benzene shows double of its molecular mass. Explain.

Answer 1

1. Osmosis. It is the phenomenon of ow of solvent from pure solvent into a solution or from a solution of lower concentration into a solution of higher concentration through a semi-permeable membrane.

2. Negative deviation. Here chloroform molecule is able to form hydrogen bond with acetone molecule.

Thus escaping tendency of the particles decreases in solution and hence the liquid mixture shows negative deviation.

3. Benzoic acid undergoes association in solution.

2C₆H₅COOH \(\rightleftharpoons\)(C₆H₅COOH)₂ Thus, the number of particles as well as colligative properties decreases. So molecular mass increases.