Question

The name of the given compound is Hexa-1,3,5-triyne.

(A) True
(B) False

Answer 1

Hint: Alkynes are unsaturated hydrocarbons containing carbon-carbon triple bonds and they are named by adding -yne as the suffix to the parent carbon chain. In case of more than one bond, preference is given to triple bonds,

Complete answer:
Unsaturated hydrocarbons containing carbon-carbon triple bonds fall under the category of alkynes. The general formula of this group of compounds is ${{\text{C}}_{\text{n}}}{{\text{H}}_{\text{2n}-\text{2}}}$. The nomenclature of alkynes is done by adding -yne as a suffix to the parent hydrocarbon chain. The following steps should be followed to name such compound:
(1) – Find the longest chain of carbon that includes all the triple bonds present.
(2) – Start numbering this longest carbon chain from the end nearest to the triple bond.
(3) – Arrange substituents' names in alphabetical order, if any.
(5) – When there is more than one triple bond in the molecule, choose the longest chain such that it contains these triple bonds and then follow rule (2) for numbering the carbon chain.
(6) – Name the compound by writing the longest carbon chain name first, then add suffix -yne to it along with the position numbers of each bond separated by commas.
Now, keeping these rules in mind let us write the name of the given compound.

(1) – Here, the longest carbon chain contains 6 carbon atoms, that is, hexane.
(2) – Numbering the carbon chain such that it includes triple bonds. In this case, the compound is symmetrical, so numbering from either side will not make any difference.

(3) – There is no substituent group. And three triple bonds are present at 1, 3, and 5 positions. So, the name of the compound will be – Hexa-1,2,3-triyne.

Hence, the answer is (A) True.

Note:
If there are both double and triple bonds present in a molecule, then the numbering of the carbon chain should start from the end which is closest to one of the multiple bonds.