Question

Which of the following are exothermic reactions?

1. neutralisation reaction between acid and alkali
2. formation of methane from nitrogen and hydrogen at 500⁰C
3. dissolution of NH₄Cl in water
4. decomposition of potassium chlorate

• A. 2 only
• B. 1, 2
• C. All
• D. 4 only

Answer 1

Answer:

B. 1, 2

• Exothermic: Reactions that release energy (usually as heat).

• Acid + Alkali: Neutralization is exothermic (releases heat).

• Methane Formation: The Haber-Bosch process is exothermic.

• Both Reactions: Release energy, therefore exothermic.

• Key Idea: Exothermic = energy out (surroundings get hotter).