Question

Statement-1: Sublimation is a purification technique that is used to separate those solid substances which change from solid to vapor state without passing through liquid state.
Statement-2: If external atmospheric pressure is reduced, then boiling point of substance decreases.
Which of the following is correct?

• A. Statement-1 and Statement-2 both are correct.
• B. Statement-1 and Statement-2 both are incorrect.
• C. Statement-1 is correct but Statement-2 is incorrect.
• D. Statement-1 is incorrect but Statement-2 is correct.

Hint:

Sublimation is used for purifying volatile substances, while changes in pressure can affect the boiling point of substances, which is particularly important in distillation and other purification techniques.

Answer 1

The Correct Option is A

Step 1: Sublimation.
Sublimation is indeed a purification process used to separate substances that change directly from solid to gas without going through the liquid phase. This is a common process for certain solids like iodine and dry ice.
Step 2: Boiling point and pressure.
The boiling point of a substance is influenced by the atmospheric pressure. If the pressure is lowered, the boiling point decreases. This is because less energy is required for the substance to vaporize.
Step 3: Conclusion.
Both statements are correct, so the correct answer is (1).