Question

Which of the following processes is an endothermic ?

• A. The aqueous NaOH and HCl solutions mixed together.
• B. Formation of ammonia by Haber process.
• C. Ice melts at room temperature.
• D. The freezing of liquid water.

Hint:

An endothermic process absorbs heat from the surroundings.

Answer 1

The Correct Option is C

Step 1: Think about heat flow:
Ask whether the surroundings lose or gain heat in each case.

Step 2: Go through the options:
Neutralisation and ammonia formation both warm their surroundings (they give out heat). Freezing water gives out latent heat to the surroundings.
Melting ice takes heat from the surroundings, which is why a drink gets cold when ice melts in it. That is endothermic, option (C).

Final Answer:
Melting of ice is the endothermic process. \[ \boxed{\text{(C)}} \]