The correct order of acidity among the following is -

1. CH₃COOH > BrCH₂COOH > ClCH₂COOH > FCH₂COOH

2. FCH₂COOH > CH₃COOH > BrCH₂COOH > ClCH₂COOH

3. BrCH₂COOH > ClCH₂COOH > FCH₂COOH > CH₃COOH

4. FCH₂COOH > ClCH₂COOH > BrCH₂COOH > CH₃COOH

The most acidic compound among the following is-

1. 

2. 

3. 

4. 

The correct order of acidity among the following is-

1. CH₂=CH₂ > CH₃-CH=CH₂ > CH₃C≡CH > CH≡CH

2. CH≡CH > CH₃-C≡CH > CH₂=CH₂ > CH₃ CH₃

3. CH≡CH > CH2=CH2 > CH₃-C≡CH > CH₃-CH₃

4. CH₃-CH₃ > CH₂=CH₂ > CH₃-C≡CH > CH≡CH

The compound that is most difficult to protonate is:

1.  

2.  

3.  

4.