Question

Decreasing order of C-C bond length is (I) `C_2H_4` (II) `C_2H_2` (III) `C_6 H_6` (IV) `C_2H_6`
A. IVgt IIgt I gt II
B. I gt II gt IV gt III
C. II gt I gt IV gt III
D. IV gt I gt III gt II.

Answer 1

Correct Answer - A

The C-C bond length is maximum in `C_2 H_6 (IV)` and minimum `C_2H_2` (II). The C-C bond length in `C_6H_6` (III) is slightly more than the C-C bond length in `C_2H_4` (I). This is due to resonance. Thus, correct order is IV gtIIIgt IgtII.