Arrange the following in decreasing order of their acidic strength and give reason for your answer.
`CH_(3)CH_(2)OH, CH_(3)COOH, ClCH_(2)COOH, FCH_(2)COOH, C_(6)H_(5)CH_(2)COOH`

Explanation

Since -I-effect of F is much stronger than that of Cl, therefore, `FCH_(2)COOH` is a stronger acid than `ClCH_(2)COOH`. Further, `C_(6)H_(5)` group has a weak -I-effect though much weaker than those of F and Cl, therefore, `C_(6)H_(5)CH_(2)COOH` is a stronger acid than `CH_(3)COOH` but weaker than `FCH_(2)COOH` and `ClCH_(2)COOH`. now `NH_(3)COOH` is a much stronger acid than `CH_(3)CH_(2)OH` because `CH_(3)COO^(-)` ion left after the loss of a proton is stabilized by resonance but no such stabilization is possible for `CH_(3)CH_(2)O^(-)` ion (obtained after loss of a proton from `CH_(3)CH_(2)OH`). thus, the overall, acidic strength decreases in the order:
`FCH_(2) COOH gt ClCH_(2)COOH gt C_(6)H_(5)COOH gt CH_(3)COOH gt CH_(3)CH_(2)OH`.