• # question_answer Index of unsaturation (H-deticiency) of ${{C}_{8}}{{H}_{10}}$ is ...... and if it has six - membered ring, it can be A)                 B)   C)                                D)  All are correct

Degree of unsaturation $=\frac{2{{n}_{1}}+2-{{n}_{2}}}{2}$where, ${{n}_{1}}=$ number of carbon atoms ${{n}_{2}}=$ number of hydrogen atoms $\therefore$ Degree of unsaturation $=\frac{2\times 8+2-10}{2}=4$ 1. Degree of unsaturation means one $C=C,$ one $C\equiv C,$ and one ring. 2. Degree of unsaturation means three $C=C,$ bond and one ring,