question_answer 79)

  Arrange the following compounds in increasing order of acidity and give a suitable explanation. Phenol, o-nitrophenol, o-cresol.

Answer:

                  Due to -1 and - R-effect of the group, o-nitrophenol is a stronger acid than phenol but do to +I-effect of the  group, o-cresol is a weaker acid than phenol. Thus, acid .strength of these three phenols increases in the order : o-cresol < phenol < o-nitrophenol.