Answer:
D) 4-ethyl-4-methylheptane
Explanation:
The rules for naming of alkanes with substituents.
1. The carbon chain with the maximum number of carbon atoms must be selected as a parent chain.
2.Numbering should be done in such a way that each substituent gets the least number.
3. Substituents whose name comes before the another substituents's name in the English alphabet is written first.
4. Substituents are written first with their location in the chain and the name of the parent chain is done. Numbers are separated from numbers by comma and numbers are separated from letters by using hyphen.
Considering (a) 3,6-dimethylheptane
<u>Violation of Rule - 2 mentioned above</u>
The numbering of the parent chain is not done in a right way. Numbering must be done such that each substituent gets the least number. So, The correct name is 2,5-dimethylheptane
Considering (b) 2-ethyl-3-methylheptane
<u>Violation of Rule - 1 mentioned above.</u>
The carbon chain with the maximum number of carbon atoms must be selected as a parent chain. The parent chain selected is of 7 carbon atoms but the parent chain is of 8 carbon atoms. So, The correct name is 3,4-dimethyloctane
Considering (c) 5-methyl-3-ethylheptane
<u>Violation of Rule - 3 mentioned above.</u>
'e' comes before 'm' . So, ethyl- is written first than methyl- . So, The correct name is 3,6-dimethyloctane
Considering (d) 4-ethyl-4-methylheptane
<u>This is a IUPAC name and following all the rules mentioned above.</u>
