MolSynapsequestion bank

MolSynapse / Question bank / p-Block Elements: Groups 17 and 18 / Halogen compounds: HX, oxoacids, bleaching powder

JEE Advanced levelSingle correct optionDifficulty 3 of 3ph046

$HOCl$ has $p K_{a} = 7.5$ . To 20 mL of 0.10 M $HOCl$ are added 10 mL of 0.10 M $NaOH$ and then 5 mL of 0.10 M $HCl$ . Ignoring any dilution effect in the ratio, the pH of the final solution is

A6.50
B7.50
C7.02
D7.98

Answer: C

Initial HOCl = 2.0 mmol. After NaOH: HOCl 1.0 mmol,

OCl X^{-}

1.0 mmol. After HCl (0.5 mmol) converts

OCl X^{-}

back: HOCl 1.5,

OCl X^{-}

0.5 mmol. pH = 7.5 + log(0.5/1.5) = 7.02.

Practice p-Block Elements: Groups 17 and 18 More on Halogen compounds: HX, oxoacids, bleaching powder

Previous questionNext question

More questions on Halogen compounds: HX, oxoacids, bleaching powder