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Question 79Asked in RRB JE CBT-1, 17 Dec 2024, Shift 2 (12:45 PM)

Which of the following is NOT a homologous series?

  1. AC₂H₄ , C₂H₆ , C₃H₆ , C₄H₈
  2. BC₂H₂ , C₂H₄ , C₃H₆ , C₄H₈
  3. CCH₄ , C₂H₆ , C₃H₈ , C₄H₁₀
  4. DC₃H₇OH , C₄H₉OH , C₅H₁₁OH_, C₆H₁₁OH
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Correct answer: (A) C₂H₄ , C₂H₆ , C₃H₆ , C₄H₈

Explanation

Official answer key: (1) C₂H₄ , C₂H₆ , C₃H₆ , C₄H₈ This question is flawed: option 2 (C₂H₂ is an alkyne, the rest are alkenes) and option 4 (C₆H₁₁OH should be C₆H₁₃OH) are also not homologous series. Option 1 is clearly not one: C₂H₄, C₃H₆, C₄H₈ are alkenes but C₂H₆ is an alkane, and C₂H₆ does not differ from C₂H₄ by CH₂. Scoring follows the official key.

From RRB JE CBT-1 PYQ 17 Dec 2024, Shift 2 (12:45 PM)

This is question 79 of RRB JE CBT-1 PYQ 17 Dec 2024, Shift 2 (12:45 PM). See all questions of this paper with answers, or attempt the paper as a timed online test to get your score and all-India rank.