Match List I with List II
|
LIST I |
LIST II |
|
A. Alcohol + Water |
I. Ideal solution |
|
B. Benzene + Toluene |
II. Positive deviation |
|
C. Water + Nitric acid |
III. Negative deviation |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A-II, B-I, C-III
A. Alcohol + Water — This matches II. Positive deviation. Adding water breaks some of the hydrogen bonds of the alcohol; the A–B attractions are weaker, the vapour pressure is higher than Raoult’s law predicts, and ethanol–water forms a minimum boiling azeotrope (about 95% ethanol).
B. Benzene + Toluene — This matches I. Ideal solution. The two molecules are so alike that A–A, B–B and A–B forces are nearly equal; the solution obeys Raoult’s law over the whole range.
C. Water + Nitric acid — This matches III. Negative deviation. The A–B attractions are stronger than in the pure liquids, the vapour pressure falls, and the mixture forms a maximum boiling azeotrope (68% nitric acid).
NCERT (2026-27 edition):
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 – “… The solutions which show a large positive deviation from Raoult’s law form minimum boiling azeotrope at a specific composition. For example, ethanol-water mixture (obtained by fermentation of sugars) on fractional distillation gives a solution containing approximately 95% by volume of ethanol.”
Non-ideal Solutions – “… The solutions that show large negative deviation from Raoult’s law form maximum boiling azeotrope at a specific composition. Nitric acid and water is an example of this class of azeotrope.”