Arrange acididy of given compounds in decreasing order
(I). `CH_(3)-N-CH_(2)-OH`
(II). `CH_(3)-NH-CH_(2)-CH_(2)-CH_(2)-OH`
(III). `(CH_(3))_(3)overset(o+)(N)-CH_(2)-CH_(2)-OH`

Options

A. IIIgtIgtII
B. IIIgtIIgtI
C. IgtIIgtIII
D. IIgtIgtIII

Answer

To determine the acidity of the given compounds, we need to analyze the structural features that influence their ability to donate protons (H⁺ ions). Here's a step-by-step breakdown of the reasoning:

### Step 1: Identify the Compounds
We have three compounds to analyze:
1. **(I)** CH₃-N-CH₂-OH
2. **(II)** CH₃-NH-CH₂-CH₂-CH₂-OH
3. **(III)** (CH₃)₃N⁺-CH₂-CH₂-OH

### Step 2: Understand the Role of Proximity
The acidity of alcohols and amines is influenced by the proximity of the nitrogen atom (N) to the hydroxyl group (OH). The closer the nitrogen is to the hydroxyl group, the more it can stabilize the negative charge that forms when the hydroxyl group donates a proton.

### Step 3: Analyze Each Compound
1. **Compound I (CH₃-N-CH₂-OH)**:
- The nitrogen (N) is directly adjacent to the hydroxyl group (OH). The lone pair on nitrogen can interact with the hydrogen of the hydroxyl group, making it less likely to release H⁺. Thus, this compound has the least acidity.

2. **Compound II (CH₃-NH-CH₂-CH₂-CH₂-OH)**:
- Here, the nitrogen is three CH₂ groups away from the hydroxyl group. The increased distance reduces the interaction between the lone pair on nitrogen and the hydroxyl group, allowing for a slightly greater tendency to donate H⁺ compared to Compound I. Therefore, this compound has moderate acidity.

3. **Compound III ((CH₃)₃N⁺-CH₂-CH₂-OH)**:
- In this case, the nitrogen is positively charged (ammonium ion). The positive charge on nitrogen is electron-withdrawing, which increases the acidity of the hydroxyl group by stabilizing the negative charge that forms when H⁺ is released. Thus, this compound has the highest acidity.

### Step 4: Arrange in Decreasing Order of Acidity
Based on the analysis:
- **Most Acidic**: (III) (CH₃)₃N⁺-CH₂-CH₂-OH
- **Moderately Acidic**: (II) CH₃-NH-CH₂-CH₂-CH₂-OH
- **Least Acidic**: (I) CH₃-N-CH₂-OH

### Final Order of Acidity
The final order of acidity in decreasing order is:
**(III) > (II) > (I)**