In the reaction sequence `underset("(small)")(C_6H_5)-CH_3overset(Cl_2//hv)rarr[X]overset(HOH//NaOH)rarr[Y]` [X] and [Y] will respectively be :

Options

A. `C_6H_5-CH_2Cl and C_6H_5-CH_2OH`
B. `C_6H_5-CH_2Cl and C_6H_5-CHO`
C. `C_6H_5-"CCl"_3 and C_6H_5COOH`
D. `C_6H_5-"CCl"_3 and C_6H_5COONa`

Answer

To solve the given reaction sequence, we will analyze each step carefully.

### Step 1: Identify the starting compound
The starting compound is toluene, represented as \( C_6H_5-CH_3 \) (where \( C_6H_5 \) is the phenyl group and \( CH_3 \) is the methyl group).

### Step 2: Reaction with \( Cl_2 \) in the presence of \( hv \)
When toluene reacts with chlorine (\( Cl_2 \)) under ultraviolet light (\( hv \)), a free radical substitution reaction occurs. The \( Cl_2 \) dissociates into two chlorine radicals (\( Cl \cdot \)).

1. The chlorine radical abstracts a hydrogen atom from the benzylic position (the carbon adjacent to the phenyl group), forming a benzylic radical:
\[ C_6H_5-CH_2 \cdot \]
2. This benzylic radical can then react with another \( Cl_2 \) molecule, leading to the substitution of the hydrogen atom with a chlorine atom. The process can continue until all hydrogen atoms at the benzylic position are replaced by chlorine.

The final product after complete chlorination at the benzylic position is:
\[ C_6H_5-CCl_3 \quad (X) \]

### Step 3: Reaction with \( H_2O \) and \( NaOH \)
Next, the product \( C_6H_5-CCl_3 \) is treated with water (\( H_2O \)) and sodium hydroxide (\( NaOH \)).

1. The hydroxide ion (\( OH^- \)) acts as a nucleophile and can substitute the chlorine atoms.
2. The substitution will occur sequentially, replacing each \( Cl \) with \( OH \). However, having three hydroxyl groups on the same carbon is unstable, leading to the loss of water molecules.

The final product after this reaction will be:
\[ C_6H_5-COONa \quad (Y) \]
This compound is sodium benzoate, which is the sodium salt of benzoic acid.

### Summary of Products
- \( X = C_6H_5-CCl_3 \) (trichloromethylbenzene)
- \( Y = C_6H_5-COONa \) (sodium benzoate)

### Final Answer
Thus, the products \( [X] \) and \( [Y] \) will respectively be:
- \( [X] = C_6H_5-CCl_3 \)
- \( [Y] = C_6H_5-COONa \)