Q1. [1] medium exam-ready
In the reaction of methane with chlorine in the presence of sunlight, what type of bond in methane is broken and what type of reaction takes place?
((A)) C–C bond; addition reaction
((B)) C–H bond; substitution reaction
((C)) C–H bond; addition reaction
((D)) C–C bond; substitution reaction
- A A C—C bond is broken and chlorine replaces a carbon atom
- B A C—H bond is broken and chlorine replaces a hydrogen atom
- C Two C—H bonds are broken and a double bond forms
- D The entire molecule is decomposed by chlorine
Generated by claude-sonnet-4-6 · 2026-06-26 01:06 · grounding rag
Model Answer
(B) C–H bond; substitution reaction
In the reaction CH₄ + Cl₂ → CH₃Cl + HCl (sunlight), the C–H bond in methane is broken and chlorine replaces a hydrogen atom. This is a substitution reaction.
Source: Chapter 4, Section 4.3.4 – Substitution Reaction
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Explanation
- The key facts are: methane has no C–C bond (single carbon), so options A and D are eliminated immediately.
- It is not an addition reaction (no double/triple bond present in saturated methane), so option C is wrong.
- Examiners expect you to name both the bond broken (C–H) and the reaction type (substitution) with a brief reason. Writing the chemical equation earns full credit.