• # question_answer Which one of the following species is most stable [IIT-JEE 1995] A) $p-{{O}_{2}}N-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}$ B) $p-C{{H}_{3}}O-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}$ C) $p-Cl-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}$ D) ${{C}_{6}}{{H}_{5}}-\overset{+}{\mathop{C}}\,{{H}_{2}}$

Nitro-group is electron withdrawing therefore decreases stability. Methoxy group is electron releasing. Therefore increases stability by donating electron. Chlorine is also electron withdrawing but its effect is less than $-N{{O}_{2}}$ group. Hence, correct order of stability.