Hint: 5th member of alkyne has the molecular formula
C6H10
Structural isomers :
Compounds having the same molecular formula but different structures (manners in which atoms are linked) are classified as structural isomers.
Chain Isomerism :
It is also known as skeletal isomerism. The components of these isomers display differently branched structures. Commonly, chain isomers differ in the branching of carbon.
Position Isomerism :
The positions of the functional groups or substituent atoms are different in position isomers. Typically, this isomerism involves the attachment of the functional groups to different carbon atoms in the carbon chain.
Possible structure the isomers of
C6H10 formula
Hence, the possible structure isomers of
C6H10 are:
(a)
HC≡C−CH2−CH2−CH2−CH3
(b)
CH3−C≡C−CH2−CH2−CH3
(c)
CH3−CH2−C≡C−CH2−CH3
(d)
(e)
(f)
(g)
IUPAC names of the isomers :
The IUPAC names are written below with structural formula.
(a)
HC≡C−CH2−CH2−CH2−CH3
Hex−1−yne
(b)
CH3−C≡C−CH2−CH2−CH3
Hex−2−yne
(c)
CH3−CH2−C≡C−CH2−CH3
Hex−3−yne
(d)
3−Methylpent−1−yne
(e)
4−Methylpent−1−yne
(f)
4−Methylpent−2−yne
(g)
3,3−Dimethylbut−1−yne
Hence, from the above definitions position and chain isomerism shown by different pairs.