The compound that is most difficult to protonate is:

1.		2.
3.		4.

What is the correct sequence of acidity for the following compounds?

Which one of the following compounds is most acidic:
 

1.		2.
3.		4.	\(\mathrm{Cl}-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{OH}\)

Which of the following orders of acid strength is correct:

1. RCOOH > ROH > HOH > HC ≡ CH

2. RCOOH > HOH > ROH > HC ≡ CH

3. RCOOH > HOH > HC ≡ CH > ROH

4. RCOOH > HC ≡ CH > HOH > ROH