A hydrocarbon A having molecular formula C ₄ H ₈ exhibits geometrical isomerism. Compound A reacts with Br ₂ in CCl ₄ to give compound B. Compound B on treatment with excess NaNH ₂ yields compound C. When compound C is passed through a red-hot iron tube at 873 K , it forms an aromatic compound D. The total number of electrons in one molecule of C and one molecule of D together is _______.

Step-by-step solution

The hydrocarbon A is an alkene with the formula C ₄ H ₈ . Since it exhibits geometrical isomerism, A must be 2-butene ( CH ₃ -CH=CH-CH ₃ ). Reaction of 2-butene with Br ₂/ CCl ₄ gives the vicinal dibromide B, which is 2,3-dibromobutane ( CH ₃ -CH(Br)-CH(Br)-CH ₃ ). Treatment of 2,3-dibromobutane with excess NaNH ₂ leads to double dehydrohalogenation, forming the internal alkyne C, which is 2-butyne ( CH ₃ -C C-CH ₃ ). One molecule of 2-butyne contains one triple bond, which consists of 2 bonds, contributing 4 elect