Lowest boiling point will be of the compound-

Options

A. 2-propanamine
B. Ethylmethylamine
C. 1-propanamine
D. N,N-dimethylmethanamine

Answer

To determine which compound has the lowest boiling point among the given amines, we need to analyze the structures and the ability of each compound to form hydrogen bonds. Here’s a step-by-step solution:

### Step 1: Identify the Compounds
We have four amines to analyze:
1. **2-Propanamine (A)**
2. **Ethyl methyl amine (B)**
3. **1-Propanamine (C)**
4. **Dimethylamine (D)**

### Step 2: Draw the Structures
- **2-Propanamine (A)**: This is a secondary amine with the structure:
\[ CH_3-CH(NH_2)-CH_3 \]
- **Ethyl methyl amine (B)**: This is also a secondary amine with the structure:
\[ CH_3-CH_2-NH-CH_3 \]
- **1-Propanamine (C)**: This is a primary amine with the structure:
\[ CH_3-CH_2-CH_2-NH_2 \]
- **Dimethylamine (D)**: This is a tertiary amine with the structure:
\[ (CH_3)_2-NH \]

### Step 3: Analyze Hydrogen Bonding
- **Hydrogen Bonding Capability**:
- Compounds A, B, and C can form hydrogen bonds because they have at least one hydrogen atom attached to the nitrogen atom.
- Compound D (Dimethylamine) does not have any hydrogen atoms attached to nitrogen, which means it cannot form hydrogen bonds.

### Step 4: Determine Boiling Points
- Compounds that can form hydrogen bonds typically have higher boiling points due to the additional intermolecular forces.
- Since compound D cannot form hydrogen bonds, it will have the lowest boiling point among the four.

### Conclusion
The compound with the lowest boiling point is **Dimethylamine (D)**.

### Final Answer
**Option D** (Dimethylamine) has the lowest boiling point.

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