What is the correct sequence of acidity for the following compounds?
1. | CH3COOH > BrCH2COOH > ClCH2COOH > FCH2COOH |
2. | FCH2COOH > CH3COOH > BrCH2COOH > ClCH2COOH |
3. | BrCH2COOH > ClCH2COOH > FCH2COOH > CH3COOH |
4. | FCH2COOH > ClCH2COOH > BrCH2COOH > CH3COOH |