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Values of dissociation constant, K_a are given as follows : … Correct order of increasing base strength of the base CN^-, F^-and NO_2^-will be :

JEE Main 2013 — Chemistry Physical Chemistry

2013mcqmedium

Values of dissociation constant, KaK_aKa​ are given as follows :  Acid KaHCN6.2×10−10HF7.2×10−4HNO24.0×10−4\begin{array}{lc}\text { Acid } & \boldsymbol{K}_{\boldsymbol{a}} \\ \mathrm{HCN} & 6.2 \times 10^{-10} \\ \mathrm{HF} & 7.2 \times 10^{-4} \\ \mathrm{HNO}_2 & 4.0 \times 10^{-4}\end{array} Acid HCNHFHNO2​​Ka​6.2×10−107.2×10−44.0×10−4​ Correct order of increasing base strength of the base CN−,F−\mathrm{CN}^{-}, \mathrm{F}^{-}CN−,F−and NO2−\mathrm{NO}_2^{-}NO2−​will be :

Official previous-year question

Held on 22 Apr 2013 · Verified 6 Jul 2026.

Options

  1. A

    F−<CN−<NO2−\mathrm{F}^{-} < \mathrm{CN}^{-} < \mathrm{NO}_2^{-}F−<CN−<NO2−​

  2. B

    NO2−<CN−<F−\mathrm{NO}_2^{-} < \mathrm{CN}^{-} < \mathrm{F}^{-}NO2−​<CN−<F−

  3. C

    F−<NO2−<CN−\mathrm{F}^{-} < \mathrm{NO}_2^{-} < \mathrm{CN}^{-}F−<NO2−​<CN−

  4. D

    NO2−<F−<CN−\mathrm{NO}_2^{-} < \mathrm{F}^{-} < \mathrm{CN}^{-}NO2−​<F−<CN−

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