Question

Double bond equivalent of the following is:

• A. 7
• B. 11
• C. 6
• D. none of these

Answer 1

The correct option is B 11

$5$ double bonds in ring $+2C=O$ double bond=$7$

$\Rightarrow 1+1=2$ ring=$2$

$1$ triple bond= $2$

Molecular formula $C_{14}{H}_9{O}_{2}N$

Observed $DBE=7+2+2=11$

$\therefore$ Calculated $DBE=C-\frac{H}{2}+\frac{N}{2}+1$

$=14-\frac{9}{2}+\frac{1}{2}+1$

$=11$