Most Important Chemistry MCQs

 

1. Which of the following is the most electronegative element?

✅ Correct Answer: B. Fluorine

Fluorine has the highest electronegativity (3.98) on the Pauling scale due to its small size and high effective nuclear charge.

2. What is the hybridization of carbon in ethene (C₂H₄)?

✅ Correct Answer: B. sp²

In ethene, each carbon is bonded to 3 atoms with 120° bond angle, indicating sp² hybridization.

3. Which of the following has the highest ionization energy?

✅ Correct Answer: D. Neon

Neon is a noble gas with a stable configuration, hence it has very high ionization energy.

4. Which one is not a greenhouse gas?

✅ Correct Answer: D. O₂

Oxygen (O₂) is not a greenhouse gas; it does not trap heat in the atmosphere like CO₂ or CH₄.

5. Which compound does not exhibit hydrogen bonding?

✅ Correct Answer: C. CH₄

CH₄ has no electronegative atom bonded to hydrogen; hence, no hydrogen bonding.