One mole of an amine (A) consumes two moles of methyl bromide to give a quaternary ammonoium salt. The amine (A) is:

Options

A. `(CH_(3))_(3)C CH_(2)NH_(2)`
B. `(CH_(3))_(2)NCH_(2)CH_(3)`
C.
D.

Answer

To solve the problem, we need to identify the amine (A) that can react with two moles of methyl bromide (CH3Br) to form a quaternary ammonium salt. Here is a step-by-step solution:

### Step 1: Understanding the Reaction
A quaternary ammonium salt is formed when an amine reacts with alkyl halides. The general reaction for the formation of a quaternary ammonium salt from an amine can be represented as:
\[ R_3N + R'X \rightarrow R_3NR' + HX \]
where \( R \) is an alkyl group, \( R' \) is another alkyl group, and \( X \) is a halide ion.

### Step 2: Analyzing the Given Information
The question states that one mole of an amine (A) reacts with two moles of methyl bromide. This indicates that the amine must have the capacity to accept two methyl groups. This is characteristic of a secondary amine, which can be further converted into a quaternary ammonium salt.

### Step 3: Identifying the Type of Amine
1. **Primary Amine (RNH2)**: Can react with one mole of methyl bromide to form a secondary amine but cannot react with two moles to form a quaternary ammonium salt.
2. **Secondary Amine (R2NH)**: Can react with two moles of methyl bromide to form a quaternary ammonium salt.
3. **Tertiary Amine (R3N)**: Can react with one mole of methyl bromide to form a quaternary ammonium salt but cannot accept two moles of methyl bromide.
4. **Quaternary Ammonium Salt (R4N+)**: Already fully substituted and cannot react further.

### Step 4: Conclusion
Since the amine (A) must be able to react with two moles of methyl bromide to form a quaternary ammonium salt, it must be a secondary amine.

### Step 5: Final Answer
The amine (A) is a **secondary amine**.