The correct order of increasing boiling points for the bases, `CH_3NH_2, (CH_3)_2NH, (CH_3)_3N` is

Options

A. `CH_3NH_2 lt (CH_3)_2NH lt (CH_3)_3N`
B. `CH_3NH_2 lt (CH_3)_3N lt (CH_3)_2NH `
C. `(CH_3)_3N lt (CH_3)_2NH lt CH_3NH_2`
D. `(CH_3)_3N lt CH_3NH_2 lt (CH_3)_2NH`

Explanation

To determine the correct order of increasing boiling points for the bases \( CH_3NH_2 \) (methylamine), \( (CH_3)_2NH \) (dimethylamine), and \( (CH_3)_3N \) (trimethylamine), we need to consider the molecular structure and the types of intermolecular forces present in each compound.

### Step 1: Identify the type of amines
- \( CH_3NH_2 \) is a primary amine (1°).
- \( (CH_3)_2NH \) is a secondary amine (2°).
- \( (CH_3)_3N \) is a tertiary amine (3°).

### Step 2: Analyze hydrogen bonding
- Primary amines can form two hydrogen bonds due to having two hydrogen atoms attached to the nitrogen atom. This allows for stronger intermolecular forces.
- Secondary amines can form one hydrogen bond because they have one hydrogen atom attached to the nitrogen atom.
- Tertiary amines do not have any hydrogen atoms attached to the nitrogen, so they cannot form hydrogen bonds. They only exhibit dipole-dipole interactions.

### Step 3: Compare boiling points based on hydrogen bonding
- The strength of intermolecular forces directly affects the boiling point. The more hydrogen bonds that can be formed, the higher the boiling point.
- Therefore, the order based on the ability to form hydrogen bonds is:
- Primary amine \( CH_3NH_2 \) (highest boiling point)
- Secondary amine \( (CH_3)_2NH \) (moderate boiling point)
- Tertiary amine \( (CH_3)_3N \) (lowest boiling point)

### Step 4: Conclude the order of boiling points
Based on the analysis:
- The correct order of increasing boiling points is:
\[ (CH_3)_3N < (CH_3)_2NH < CH_3NH_2 \]

### Final Answer
The correct order of increasing boiling points for the bases \( CH_3NH_2, (CH_3)_2NH, (CH_3)_3N \) is:
\[ (CH_3)_3N < (CH_3)_2NH < CH_3NH_2 \]