The correct order of basicity of amines in water is:

Options

A. `(CH_3)_2NHgt(CH_3)_3NgtCH_2NH_2`
B. `CH+3NH_2gt(CH_3)_3NHgt(CH_3)_3N`
C. `(CH_3)_3Ngt(CH_3)_2NHgt(CH_3NH_2`
D. `(CH_3)_3NgtCH_3NH_2gt(CH_3)_2NH`

Explanation

To determine the correct order of basicity of amines in water, we need to consider the structure of the amines and the effects of the alkyl groups on the nitrogen atom. Here's a step-by-step solution:

### Step 1: Understand the Basicity of Amines
Basicity in amines is primarily influenced by the availability of the lone pair of electrons on the nitrogen atom. The more available the lone pair is for protonation, the more basic the amine.

### Step 2: Consider the Effects of Alkyl Groups
Alkyl groups, such as methyl groups (–CH3), exhibit a +I (inductive) effect, which increases the electron density on the nitrogen atom, enhancing its basicity. However, the steric hindrance caused by bulky groups can also affect basicity.

### Step 3: Analyze Different Types of Amines
1. **Primary Amine (e.g., CH3NH2)**: Has one alkyl group. The +I effect is present but less pronounced than in secondary and tertiary amines.
2. **Secondary Amine (e.g., (CH3)2NH)**: Has two alkyl groups. The +I effect is stronger, and there is less steric hindrance compared to tertiary amines.
3. **Tertiary Amine (e.g., (CH3)3N)**: Has three alkyl groups. While the +I effect is maximized, the steric hindrance around the nitrogen atom makes it less accessible for protonation.

### Step 4: Compare the Basicity
- **Secondary Amine**: Most basic due to a balance of +I effect and minimal steric hindrance.
- **Tertiary Amine**: Less basic than secondary due to significant steric hindrance despite having the strongest +I effect.
- **Primary Amine**: Least basic due to having only one alkyl group and a weaker +I effect compared to secondary and tertiary amines.

### Step 5: Conclusion
The correct order of basicity of amines in water is:
**Secondary Amine > Tertiary Amine > Primary Amine**

### Final Answer
The correct order of basicity of amines in water is:
**Option A: Secondary > Tertiary > Primary**

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