For C5H12, there are a total of 3 unique isomers considering both alkane and cycloalkane families.1. Alkane isomers:C5H12 is an alkane with the general formula CnH2n+2. There are 3 isomers in the alkane family:a n-Pentane straight-chain : CH3-CH2-CH2-CH2-CH3b Isopentane branched : CH3-CH CH3 -CH2-CH3c Neopentane branched : CH3-C CH3 32. Cycloalkane isomers:Cycloalkanes have the general formula CnH2n. However, for C5H12, there are no cycloalkane isomers possible because the smallest cycloalkane is cyclopropane C3H6 , and a 5-carbon cycloalkane would have the formula C5H10, not C5H12.So, there are a total of 3 unique isomers for C5H12 in the alkane and cycloalkane families.