The correct order of increasing acidic strength is

Options

A. `"phenol"lt"ethanol"lt"chloroacetic acid"lt"acetic acid"`
B. `"ethanol"lt"phenol"lt"chloroacetic acid"lt"acetic acid"`
C. `"ethanol"lt"phenol"lt"acetic acid"lt"chloroacetic acid"`
D. `"chloroacetic acid"lt"acetic acid"lt"phenol"lt"ethanol"`

Explanation

To determine the correct order of increasing acidic strength among the given compounds (ethanol, phenol, acetic acid, and chloroacetic acid), we will analyze the acidity of each compound based on their structures and the effects of substituents.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds we need to compare are:
- Ethanol (C2H5OH)
- Phenol (C6H5OH)
- Acetic Acid (CH3COOH)
- Chloroacetic Acid (ClCH2COOH)

2. **Understand the General Trend in Acidity**:
- Acidity generally increases in the order of alcohols < phenols < carboxylic acids. This is due to the stability of the conjugate base formed after deprotonation.
- Alcohols (like ethanol) are the least acidic, followed by phenols, and then carboxylic acids (like acetic acid and chloroacetic acid) which are the most acidic.

3. **Compare Ethanol and Phenol**:
- Ethanol is an alcohol and has a hydroxyl (-OH) group.
- Phenol, on the other hand, has a hydroxyl group attached to a benzene ring, which allows for resonance stabilization of its conjugate base (phenoxide ion).
- Therefore, phenol is more acidic than ethanol.

4. **Compare Acetic Acid and Chloroacetic Acid**:
- Acetic acid (CH3COOH) has a methyl group attached to the carboxylic acid.
- Chloroacetic acid (ClCH2COOH) has a chlorine atom attached to the carbon adjacent to the carboxylic acid. Chlorine is an electron-withdrawing group, which stabilizes the conjugate base (chloroacetate ion) more than the methyl group does in acetic acid.
- Thus, chloroacetic acid is more acidic than acetic acid.

5. **Establish the Order of Acidity**:
- From the analysis:
- Ethanol < Phenol < Acetic Acid < Chloroacetic Acid
- Therefore, the increasing order of acidic strength is:
- Ethanol < Phenol < Acetic Acid < Chloroacetic Acid

6. **Select the Correct Option**:
- This order corresponds to option 3: ethanol, phenol, acetic acid, chloroacetic acid.

### Final Answer:
The correct order of increasing acidic strength is:
**Ethanol < Phenol < Acetic Acid < Chloroacetic Acid (Option 3)**