Arrange the following in increasing order of acidic strength:
`ClCH_(2)COOH, CH_(3)CH_(2)COOH, ClCH_(2)CH_(2)COOH, CH_(3)COOH`.

Explanation

To arrange the compounds in increasing order of acidic strength, we need to consider the effects of substituents on the carboxylic acid group (-COOH). The acidic strength of carboxylic acids is influenced by the presence of electron-withdrawing groups (EWGs) and electron-donating groups (EDGs).

### Step-by-Step Solution:

1. **Identify the Compounds**:
The compounds given are:
- ClCH₂COOH (Compound 1)
- CH₃CH₂COOH (Compound 2)
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