Identify the compounds A, B, C and D.
`CH_(3)CN overset(H_(2)O //H^(+))toA overset(NH_(3))toB overset("heat")toC overset(Br_(2)//KOH)toD`

Explanation

To identify the compounds A, B, C, and D in the given reaction sequence, we can follow these steps:

### Step 1: Identify Compound A
The starting compound is methyl cyanide (CH₃CN). When it undergoes hydrolysis in the presence of water and an acid (H⁺), it converts to a carboxylic acid. The reaction can be summarized as:
\[ \text{CH}_3\text{CN} + \text{H}_2\text{O} \xrightarrow{\text{H}^+} \text{CH}_3\text{COOH} \]
Thus, Compound A is **acetic acid (CH₃COOH)**.

### Step 2: Identify Compound B
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