Q18 / 75 · JEE Main 2026 (23 January Shift 1) · Chemistry
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 :
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 :
- ABoth Statement I and Statement II are true
- BStatement I is true but Statement II is false
- Correct answerCBoth Statement I and Statement II are false
- DStatement I is false but Statement II is true
Solution
Statement I: Sublimation is a process where a solid directly converts into vapor without passing through the liquid state. It is used to separate sublimable compounds from non-sublimable impurities. It is not specifically used for compounds based on having a low melting point, but rather based on their ability to sublime. Thus, Statement I is false.
Statement II: The boiling point of a liquid is the temperature at which its vapor pressure equals the external pressure. If the external pressure is reduced, the vapor pressure required to reach boiling is lower, which occurs at a lower temperature. Therefore, the boiling point decreases as the external pressure is reduced. Thus, Statement II is false.
Since both statements are false, the correct option is (3).
Statement II: The boiling point of a liquid is the temperature at which its vapor pressure equals the external pressure. If the external pressure is reduced, the vapor pressure required to reach boiling is lower, which occurs at a lower temperature. Therefore, the boiling point decreases as the external pressure is reduced. Thus, Statement II is false.
Since both statements are false, the correct option is (3).
Hence, the correct answer is option: 'C'.