Question

'A' is planar cyclic hydrocarbon in which all the carbon-carbon bonds are of same length and are less than $1.54\stackrel{o}{A}$ but more than $1.34\stackrel{o}{A}$. The $C-C$ bond angle in hydrocarbon will be:

• A. ${109}^o{28}^{\prime }$
• B. ${100}^o$
• C. ${180}^o$
• D. ${120}^o$

Answer 1

The correct option is D ${120}^o$

Since it is less than single bond length and greater than double bond length , therefore it is a resonanted planar structure. Option (A) is the tetrahedral angle ,while option (B) is not a possible angle because no of bonds (C-C) is not an integer and option (C) can't be cyclic,therefore option (D) is the answer.