Among the isomeric alkanes of molecular formula C5H12, identify the one that on photochemical chlorination yields

Three isomeric monochlorides.

To have three isomeric monochlorides, the isomer of the alkane of the molecular formula C5H12 should contain three different types of H-atoms. Therefore, the isomer is n-pentane. It can be observed that there are three types of H atoms labelled as a, b and c in n-pentane as shown below : -