All of the following names are incorrect or incomplete. In each case, draw the structure (or a possible structure) and name it correctly.
(a) 2-methylethyl pentane
The name of the compound given is 2-methylethyl pentane.
The given name is incorrect as the substituent (-CH3,-C2H5) on the main carbon atom should be named according to alphabetical order that is it should be ethyl methyl pentane .
Also the location of one of the substituent on the main carbon atoms is not mentioned .
As both the methyl and ethyl groups (-CH3,-C2H5)are bonded to second carbon atom ,the correct name will be 2,2-ethyl methyl pentane .
The name of the compound given is 2-ethyl-3-methylpentane .
The given name is incorrect because according to IUPAC rules we have to select the longest chain so the longest chain according this is shown in the figure .so the longest chain is hexane molecule
The name of the compound is given as 3-dimethylhexane.
The given name is incorrect because according to IUPAC rules every substituent should be counted and here one methyl group is not counted so the correct naming is 3,3-dimethyl hexane .
(d) 4-isobutyl heptane
The name of the compound given is 4-isobutyl heptane.