Arrange the following given acids in decreasing order of their Ka values F C H 2 C O O H ( P ) , C l C H 2 C O O H ( Q ) , O 2 N C H 2 C O O H ( R ) , N C C H 2 C O O H ( S )

Step-by-step solution

Acidic character α stability of conjugate base (anion) As stability of anion ∝ − M and – I effect . - C l and - F have ( – I > + M e f f e c t ) in which F is more electron withdrawing due to greater electronegativity. N O 2 and C N have both - I and - M effect with N O 2 being more electron withdrawing. Order of - I - effect - N O 2 > C N > - F > - C l Hence, order of acidity ka will be O 2 N C H 2 C O O H > N C C H 2 C O O H > F C H 2 C O O H > C l C H 2 C O O H