Identify A and B in each of the following processes.
`CH_3 CH_2 Cl overset(NaCN)toA underset(Ni//H_2)overset("Reduction")to B`

Explanation

To solve the problem, we need to identify the compounds A and B in the given reactions. Let's break down the steps:

### Step 1: Identify the starting compound
The starting compound is **CH₃CH₂Cl**, which is known as **Chloroethane**.

### Step 2: Reaction with NaCN
When chloroethane (CH₃CH₂Cl) reacts with sodium cyanide (NaCN), a nucleophilic substitution reaction occurs. The cyanide ion (CN⁻) replaces the chlorine atom (Cl) in chloroethane.

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