Monochlorination of n-pentane under photochemical conditions yields a compound 'P' which is capable of exhibiting optical activity. 'P' on further chlorination gives a mixture of dichloro compounds. The number of structurally distinct dichloro compounds obtained (ignoring stereoisomers) is:

Step-by-step solution

The structure of n-pentane is CH₃-CH₂-CH₂-CH₂-CH₃ . Monochlorination of n-pentane gives three structural isomers: 1-chloropentane, 2-chloropentane, and 3-chloropentane. Among these, only 2-chloropentane ( CH₃-C^ * HCl-CH₂-CH₂-CH₃ ) contains a chiral carbon atom and can exhibit optical activity. Thus, the compound 'P' is 2-chloropentane. Further chlorination of 2-chloropentane can take place at any of the five carbon atoms, yielding the following structurally distinct dichloro compounds: 1. Chlorination at C-1: CH₂C