In the presence of sunlight, benzene reacts with $$Cl_2$$ to give product X. The number of hydrogens in X is ______.

We need to determine the product X when benzene reacts with $$Cl_2$$ in the presence of sunlight, and count the number of hydrogen atoms in X.

In the presence of sunlight (UV light), benzene undergoes an addition reaction with chlorine (not the usual electrophilic substitution that occurs in the presence of a Lewis acid catalyst like AlCl$$_3$$).

The addition of three molecules of $$Cl_2$$ to benzene gives benzene hexachloride (BHC), also known as Lindane:

$$C_6H_6 + 3Cl_2 \xrightarrow{h\nu} C_6H_6Cl_6$$

In this reaction, the three double bonds of benzene are broken, and chlorine atoms add across each double bond.

The product $$C_6H_6Cl_6$$ (1,2,3,4,5,6-hexachlorocyclohexane) has 6 hydrogen atoms.

Therefore, the correct answer is 6.