JEE Main 2026 · 23 January · morning · Single correct · +4 / −1
Given below are two statements :
Statement I : Sublimation is used for the separation and purification of compounds with low melting point.
Statement II : The boiling point of a liquid increases as the external pressure is reduced. In the light of the above statements,
choose the correct answer from the options given below :
- (a) Both Statement I and Statement II are false
- (b) Statement I is true but Statement II is false
- (c) Both Statement I and Statement II are true
- (d) Statement I is false but Statement II is true
Answer and solution
Answer (a) Both Statement I and Statement II are false
Solution
Chemistry ma’am · 4 steps
Sublimation needs a solid that skips melting, and lower pressure makes a liquid boil sooner, not later.
- Statement I. Sublimation works only for solids that turn straight into vapour on heating, without melting first, such as camphor, naphthalene and iodine. It separates such sublimable solids from non-sublimable impurities. A low melting point is not the deciding property, so Statement I is false.
- Boiling point rule. A liquid boils when its vapour pressure becomes equal to the external pressure.
Boiling: pᵥₐₚₒᵤᵣ = pₑₓₜₑᵣₙₐₗ
- Statement II. If the external pressure is lowered, the vapour pressure reaches it at a lower temperature. So the boiling point decreases. This is why distillation under reduced pressure is used for liquids that decompose at their normal boiling point, such as glycerol. Statement II is false.
- So. Both statements are false, which is option (a).
The idea to keep. Match each purification method to the property it uses: sublimation for solids that vaporise without melting, and reduced pressure for liquids that would decompose at their normal boiling point.
Answer from the NTA final answer key. Solution by PrepWiser.