Question

Which hydrocarbon belongs to the Alkyne homologous series?

(A) CHCH
(B) CH2CH2
(C) CH3CH3
(D) CH3CH2CH2CH3

Answer 1

(A) CHCH

Step-by-step explanation:

Hello,

Alkynes are formed when triple bonds are formed between carbons, it means that due to the triple bonds, three bonds are already exhausted and carbon atoms need four bonds to attain the octet, for that reason, an extra bond is allowed. Now, such extra bond, when talking about hydrocarbons is filled with hydrogens, for that reason the alkyne should be (A) CHCH as it also accomplishes the following formula which is not accomplished by the rest of the options:

`C_nH_(2n-2)`

Since n=2, we have:

`C_2H_2`

Which matches with CHCH.

Best regards.