Question

list the following aqueous solutions in order of their expected freezing point: 0.50m CaCl2, 0.15m NaCl, 0.10m HCl, 0.05m CH3 COOH, 0.10m C12 H22 O11

Answer 1

CaCl2 -------> Ca+2 + 2 Cl-

1 mole is dissociated into 3 moles of particles.

the concentration will be = 0.5 * 3 = 1.5 m

NaCl ------> Na+ + Cl-

1 mole is dissociated into 2 moles of particles

Concentration will be = 0.15 * 2 = 0.3 m

HCl ------> H+ + Cl-

1 mole is dissociated into 2 moles of particles

concentration will be = 0.1 *2 = 0.2 m

2 CH3COOH ------> (CH3COOH)2

2 moles of acetic acid is dimerized to 1 mole

concentration will be = 0.05 * 1/2 = 0.025 m

C12H22O11 -----> C12H22O11

so from the equation concentration will be = 0.1 m

number particles concentration is directly proportional to freezing point of solution.

Hence the order is CaCl2 > NaCl > HCl > C12H22O11 > CH3COOH