Question

Assertion (A): When water at 0°C freezes to form ice the temperature stays at 0°C, till all the water freezes.

Reason (R): During change of state from water to ice no amount of heat is absorbed or given out.

Options

• Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

• Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).

• Assertion (A) is false, but Reason (R) is true.

• Assertion (A) is true, but Reason (R) is false.

Answer 1

Assertion (A) is true, but Reason (R) is false.

Explanation:

During freezing, water at 0°C changes to ice at 0°C while the temperature remains constant, so A is true. Heat is given out during freezing (336 kJ per kg), so the statement that no heat is absorbed or given out is false.