Arrange the following in increasing order of their acid strength: methylamine, dimethylamine, aniline, N-methylaniline.

Explanation

To determine the increasing order of acid strength for the compounds methylamine, dimethylamine, aniline, and N-methylaniline, we need to analyze the stability of their conjugate bases. The more stable the conjugate base, the stronger the acid.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- Methylamine (CH₃NH₂)
- Dimethylamine (CH₃)₂NH
- Aniline (C₆H₅NH₂)
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