Q. Which of the following has the maximum acidic strength?

 2958  280 JIPMERJIPMER 2004Organic Chemistry – Some Basic Principles and Techniques Report Error

Solution:

-nitrobenzoic acid is the strongest acid among these. group is a powerful electron withdrawing group and it has most effect when present at -position. It is also known as o-effect. Due to its electron withdrawing nature electron density on H-atom in - COOH group becomes very less, hence it can be easily donated.