Question

The number of chlorine atoms present in the organic products \(X\) and \(Y\) of the following reactions respectively are: \[ {C6H6 + Cl2 →[Anhyd. AlCl3][dark] X} \] \[ {C6H6 + 3Cl2 →[500K] Y} \]

• A. 1 and 6
• B. 6 and 3
• C. 3 and 3
• D. 6 and 6

Hint:

Benzene with \(Cl_2/AlCl_3\) gives chlorobenzene by substitution, whereas benzene with \(3Cl_2\) gives benzene hexachloride by addition.

Answer 1

The Correct Option is A

To solve this problem, let's analyze each reaction separately to determine the organic products \(X\) and \(Y\) involved and the number of chlorine atoms present in each.

1. In the first reaction:

\(C_6H_6 + Cl_2 \overset{\text{Anhyd. AlCl}_3}{\longrightarrow} X\)

This is an example of a Friedel-Crafts alkylation reaction where benzene \((C_6H_6)\) reacts with chlorine \((Cl_2)\) in the presence of an anhydrous aluminum chloride catalyst \((\text{AlCl}_3)\). This reaction results in the substitution of one hydrogen atom in benzene with one chlorine atom, forming chlorobenzene \((C_6H_5Cl)\).

Therefore, \(X = C_6H_5Cl\), which contains 1 chlorine atom.

1. In the second reaction:

\(C_6H_6 + 3Cl_2 \overset{500\text{K}}{\longrightarrow} Y\)

At a higher temperature of 500 K, benzene undergoes an addition reaction with chlorine. This leads to the formation of a fully chlorinated product, benzene hexachloride or hexachlorocyclohexane \((C_6H_6Cl_6)\). All six hydrogen atoms in benzene are replaced by chlorine atoms.

Therefore, \(Y = C_6H_6Cl_6\), which contains 6 chlorine atoms.

Combining these results, the number of chlorine atoms in products \(X\) and \(Y\) are 1 and 6 respectively.

Thus, the correct answer is: 1 and 6.