Question

Consider the hydrocarbon below.


What is the name of this hydrocarbon?
1-ethyne
1-pentyne
1-ethane
1-butyne

Answer 1

The correct option is A.
Ethyne belongs to the alkyne family of the hydrocarbon and it is the simplest member of that family. It is made up of two carbon atoms and two hydrogen atom that has one triple bond between them. Ethyne is a gas at room temperature and it is widely used as fuel. As a fuel, it is easily ignited and it burn with a sooty flame; the gas is lighter than air.
Looking at the diagram given, you can determine the number of carbon in the structure by counting the number of joints in the structure, that is the location of the carbon in the structure. The structure we are given have two joints, which means two carbons are present. Out of all the options given, it is only ethyne that has 2 carbons and a triple bond in its structure. Pentyne has 5 carbon, butyne has 4 and ethane is an alkane which has 5 carbon atoms and single bonds in its molecule.

Answer 2

Answer: Option (b) is the correct answer.

Explanation:

The given hydrocarbon has five carbon atoms. Also, there is a triple bond at the extreme right end, therefore it is an alkyne.

Since there is only a triple bond in the give hydrocarbon chain. So, numbering will be started from extreme right end in order to give least number to the triple bond.

Hence, name of the given hydrocarbon is 1-pentyne.