In the reaction sequence `C_6H_5CHOoverset(NaCN//HCl)rarr(X)overset(H_2"O"//H^o+)rarr` product, Product will be

Options

A. Optically inative acid
B. Optically inactive `alpha-` hydroxy acid
C. Racemic mixture of two optically active `alpha`- hydroxy acids
D. Racemic mixture of two optically active secondary alcohols

Answer

To solve the question step by step, we will analyze the reaction sequence provided and identify the product formed.

### Step 1: Identify the starting compound
The starting compound is benzaldehyde, which has the formula \( C_6H_5CHO \).

### Step 2: Reaction with NaCN
When benzaldehyde reacts with sodium cyanide (NaCN), the cyanide ion (CN⁻) acts as a nucleophile. The carbonyl carbon (C=O) in benzaldehyde is electrophilic due to the electronegativity of oxygen. The reaction can be represented as follows:

\[ C_6H_5CHO + NaCN \rightarrow C_6H_5CH(OH)CN \]

In this step, the CN⁻ attacks the carbonyl carbon, leading to the formation of a cyanohydrin. The product at this stage is \( C_6H_5CH(OH)CN \).

### Step 3: Treatment with H₂O and H⁺
Next, the cyanohydrin undergoes hydrolysis when treated with water (H₂O) in the presence of an acid (H⁺). During hydrolysis, the CN group is converted into a carboxylic acid (COOH). The reaction can be represented as follows:

\[ C_6H_5CH(OH)CN + H_2O \rightarrow C_6H_5CH(OH)COOH \]

The final product is \( C_6H_5CH(OH)COOH \), which is an alpha-hydroxy acid.

### Step 4: Determine the chirality of the product
The carbon atom that is bonded to the hydroxyl group (OH) and the carboxylic acid group (COOH) is a chiral center because it is attached to four different groups: a benzene ring (C₆H₅), a hydroxyl group (OH), a carboxylic acid group (COOH), and a hydrogen atom (H). Therefore, the product is optically active.

### Step 5: Identify the correct option
From the analysis, the product formed is an optically active alpha-hydroxy acid, which is a secondary alcohol. Thus, the correct answer is:

**Product: An optically active alpha-hydroxy acid (secondary alcohol)**

### Summary of the Steps:
1. Identify the starting compound (benzaldehyde).
2. React with NaCN to form a cyanohydrin.
3. Hydrolyze the cyanohydrin to form an alpha-hydroxy acid.
4. Determine the chirality of the product (it is optically active).
5. Identify the correct option based on the product formed.