Which of the following statements are correct regarding ideal and non-ideal solutions?
A. An ideal solution obeys Raoult’s Law over the entire range of concentration.
B. A non-ideal solution does not obey Raoult’s Law over the entire range of concentration.
C. A mixture of bromoethane and chloroethane is an example of non-ideal solution.
D. A mixture of chloroform and acetone is an example of ideal solution.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A and B only
An ideal solution obeys Raoult’s law over the entire range of concentration and a non-ideal solution does not; bromoethane + chloroethane is one of the nearly ideal pairs. A non-ideal solution shows a negative deviation when the A–B attractions are stronger than the A–A and B–B attractions, as in chloroform + acetone, which form a hydrogen bond with each other.
(A) An ideal solution obeys Raoult’s Law over the entire range of concentration. — Correct. This is the definition of an ideal solution.
(B) A non-ideal solution does not obey Raoult’s Law over the entire range of concentration. — Correct. This is the definition of a non-ideal solution.
(C) A mixture of bromoethane and chloroethane is an example of non-ideal solution. — Incorrect. The two haloalkanes are very alike in size and polarity, so their mixture is nearly ideal.
(D) A mixture of chloroform and acetone is an example of ideal solution. — Incorrect. The H of chloroform forms a hydrogen bond with the oxygen of acetone, so the mixture shows a negative deviation; it is non-ideal.
NCERT (2026-27 edition):
Ideal Solutions – “The solutions which obey Raoult’s law over the entire range of concentration are known as ideal solutions. … A perfectly ideal solution is rare but some solutions are nearly ideal in behaviour. Solution of n-hexane and n-heptane, bromoethane and chloroethane, benzene and toluene, etc. fall into this category.”
Non-ideal Solutions – “When a solution does not obey Raoult’s law over the entire range of concentration, then it is called non-ideal solution. … Similarly, a mixture of chloroform and acetone forms a solution with negative deviation from Raoult’s law.”