Q1. [1]
Which of the following set of compounds does not belong to same homologous series ?
- (A) CH₄ and C₄H₁₀
- (B) C₂H₆ and C₃H₈
- (C) C₃H₈ and C₅H₁₂
- (D) C₄H₈ and C₅H₁₂
Previously asked in CBSE board exam
2026 31/5/1 Q18
Generated by claude-sonnet-4-6 · 2026-06-15 06:46 · grounding rag
Model Answer
(D) C₄H₈ and C₅H₁₂
C₄H₈ follows the general formula CₙH₂ₙ (alkene series), while C₅H₁₂ follows CₙH₂ₙ₊₂ (alkane series). They belong to different homologous series.
Explanation
- Check the general formula for each option: alkanes = CₙH₂ₙ₊₂; alkenes = CₙH₂ₙ.
- Options A, B, C all contain pairs of alkanes (CH₄, C₂H₆, C₃H₈, C₄H₁₀, C₅H₁₂ all fit CₙH₂ₙ₊₂).
- In option D, C₄H₈ is an alkene and C₅H₁₂ is an alkane — different series, so they do not belong to the same homologous series.
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