Ethyl bromide reacts with alcoholic solution of KCN and AgCN to give different products having same molecular formula. These further react with other reagents to form different products.
Complete the reaction:
`CH_(3)CH_(2)Br overset(alc. KCN)to A overset(Na, C_(2)H_(5)OH)to B`

Explanation

To solve the problem step by step, we will analyze the reactions of ethyl bromide (C2H5Br) with alcoholic KCN and AgCN, leading to different products with the same molecular formula.

### Step 1: Reaction of Ethyl Bromide with Alcoholic KCN
Ethyl bromide (C2H5Br) reacts with alcoholic potassium cyanide (KCN). In this reaction, the cyanide ion (CN⁻) acts as a nucleophile and attacks the carbon atom bonded to the bromine atom, leading to the substitution of bromine.

**Reaction:**
\[
\text{C}_2\text{H}_5\text{Br} + \text{KCN} \xrightarrow{\text{alc.}} \text{C}_2\text{H}_5\text{CN} + \text{KBr}
...