Final answer:
The structure of 5-methylhept-3-yne consists of a seven-carbon chain with a triple bond at the third carbon and a methyl group attached to the fifth carbon. CH3-CH2-C≡C-CH2-CH(CH3)-CH3
Step-by-step explanation:
To draw the structure of 5‑methylhept‑3‑yne, you start with the heptane parent chain, which has 7 carbon atoms. Since the molecule is an alkyne, this means there is a triple bond within the carbon chain. According to the name, the triple bond starts at the third carbon (counting from the end of the chain that gives the substituents the lowest possible numbers), making it hept-3-yne. The methyl (CH3) group is attached to the fifth carbon atom.
The structure is as follows:
CH3-CH2-C≡C-CH2-CH(CH3)-CH3
Note that each carbon atom not involved in the triple bond will have enough hydrogen atoms to complete four covalent bonds, following the tetravalency of carbon. However, at the triple bond, only one hydrogen atom will be attached to one of the carbon atoms involved in the alkyne.