Question

Arrange the following in decreasing order of their acidic strengths.

• A. A > C > B > D
• B. A > D > B > C
• C. A > D > C > B
• D. D > A > C > B

Answer 1

The correct option is C A > D > C > B

Acid strength of a compound depends on the stability of the conjugate base formed.
Acidic strength is directly proportional to the electronegativity of atom to which the hydrogen attached.
The positive charge on electronegativity atoms will increase their electronegativity power further. Thus, $O^{+}$ and $N^{+}$ are more electronegative than O and N.
In the given compounds, the order of electronegativity of the atoms is,
$O^{+}>N^{+}>O>N$
Therefore, the ease of release of $H^{+}$ follows the order,
(A) > (D) > (C) > (B)
Hence, the decreasing order of acidic strength is,
(A) > (D) > (C) > (B)