A non-ideal solution was prepared by mixing 30 mL chloroform and 50 mL acetone. The volume of mixture will be

> 80 mL
< 80 mL
=80 mL
≥80 mL

Solution

Chloroform and acetone form a non-ideal solution in which A......B type of interactions are readily seen due to intensive H-bonding instead of A......A and B......B type. Therefore, the solution shows negative deviation from Raoult's law
i.e. Δ_mix = -ve; ΔH_mix = -ve
∴ Total volume of solution is less than 80 ml.

A mixture of components A and B will show –ve deviation when

ΔV_mix > 0
ΔH_mix < 0
A–B interaction is weaker than A–A and B–B interactions
A–B interaction is stronger than A–A and B–B interactions

Solution

A solution containing A and B components shows negative deviation when A–A and B–B interactions are weaker than that of A–B interactions. For such solutions.ΔH = –ve and ΔV = –ve.

The vapour pressure of two liquids‘P’ and‘Q’ are 80 and 60 torr, respectively. The total vapour pressure of solution obtained by mixing 3 mole of P and 2 mole of Q would be

72 torr
140 torr
68 torr
20 torr

Solution

A solution containing components A and B follows Raoult’s law when

A – B attraction force is greater than A – A and B – B
A – B attraction force is less than A – A and B– B
A– B attraction force remains same as A–A and B –B
volume of solution is different from sum of volume of solute and solvent

Solution

These two components A and B follows the condition of Raoult’s law if the force of attraction between A and B is equal to the force of attraction between A and A or B and B.

If 20 g of a solute was dissolved in 500 ml.of water and osmotic pressure of the solution was found to be 600 mm of Hg at 15ºC, then molecular weight of the solute is :

1000
1200
1400
1800

Solution

Vapour pressure of benzene at 30°C is 121.8 mm Hg. When 15 g of a non volatile solute is dissolved in 250 g of benzene its vapour pressure decreased to 120.2 mm Hg. The molecular weight of the solute (Mo. wt. of solvent = 78)

356.2
456.8
530.1
656.7

Solution

The molal freezing point constant for water is 1.86ºC.Therefore, the change in freezing point of 0.1 molal of NaCl solution in water is expected to be