question_answer

                Which one of the following compounds is most acidic?                                                                  

A)                 \[Cl-C{{H}_{2}}-C{{H}_{2}}-OH\]

B)                  

C)                  

D)                

Correct Answer: B

Solution :

                Phenols are much more acidic than alcohols, due to the stabilization of phenoxide ion resonance.                                 Phenoxide ion is stabilized due to following resonating structures:                                 While in alcohols                                 Ortho nitrophenol is most acidic because in it \[-N{{O}_{2}}\] electron attracting group is attached on ortho position which helps in stabilizing of negative charge on the oxygen of phenoxide ion Hence, due to this reason acidic character of phenol is increased, while on attachment of \[C{{H}_{3}}\] group (electron donating group) acidic strength of phenol is decreased in cresol due to destabihzation of phenoxide ion.