The hydrocarbon of molecular mass 72 gives a single monochloride and two dichlorides on photochlorination is

Step-by-step solution

The hydrocarbon of mass 72 is C 5 H 12 . Since there is one monoclhoro derivative, the compound has twelve equivalent H's in four equivalent C H 3 ′ s . The compound is ( C H 3 ) 4 C (2,2-dimethylpropane) and the chloro derivative are as follows