A compound A contains C and H only and has molecular mass 72. It's photochlorination gives a mixture containing only one monochloro and two dichloro hydrocarbons. The IUPAC name is

Step-by-step solution

C ₅ H ₁₂ , pentane has molecular mass 72 ~g i.e. the isomer of pentane which yields single monochloro derivative and two dichloro derivative is 2, 2-dimethyl propane as it has all equivalent hydrogens.