Relative Strength of Organic Acids
(i) A compound is acidic in nature, if its conjugate base can stabilize through resonance. Thus phenol is acidic while ethanol is neutral because the conjugate base of phenol 
can be stabilized through resonance while that of alcohol 
can not.
(ii) Hydrogen atom attached to sp-hybridized carbon is more acidic than that on 
hybridized carbon which in turn is more acidic than that on 
hybridized carbon.
Thus, 
