Question

A non-ideal solution was prepared by mixing 30 mL chloroform and 50 mL acetone. The volume of mixture will be
(a) > 80 mL
(b) < 80 mL
(c) = 80 mL
(d) $\geq 80 mL$

Answer 1

since a mixture of chloroform and acetone shows negative deviation the volume will be less than 80 ml
option B is the answer

Answer 2

Answer : The correct option is, (b) < 80 ml

Explanation :

According to the Rouault's law, there are two types of deviation which are negative deviation and positive deviation.

In negative deviation, the A-A interactions and B-B interactions are weaker that the A-B interactions that means A-B interactions are more due hydrogen bonding. The example of negative deviation is, chloroform & acetone form a non-ideal solution. The volume of solution will always be more.

In positive deviation, the A-A interactions and B-B interactions are stronger that the A-B interactions. The example of positive deviation is, acetone & benzene form a non-ideal solution. The volume of solution will always be less.

As per question, the chloroform & acetone form a non-ideal solution and the they shows negative deviation. That means,

$\Delta V_{mix}=-ve$

$\Delta H_{mix}=-ve$

So, the total volume of solution = less than (30 + 50 ml) or less than 80 ml or < 80 ml