1.00 mmol of Na2SO3 (oxidised to sulphate) is titrated with 0.0200 M KMnO4 under different conditions. Which volumes of permanganate solution are required?

Acidic medium (to Mn^2+): 20.0 mL

Neutral medium (to MnO2): 33.3 mL

Strongly alkaline medium (to MnO4^2-): 100.0 mL

Acidic medium (to Mn^2+): 20.0 mL

Neutral medium (to MnO2): 33.3 mL

Strongly alkaline medium (to MnO4^2-): 100.0 mL

Acidic medium (to Mn^2+): 33.3 mL

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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3rx215

1.00 mmol of $Na X_{2} SO X_{3}$ (oxidised to sulphate) is titrated with 0.0200 M $KMnO X_{4}$ under different conditions. Which volumes of permanganate solution are required?

AAcidic medium (to $Mn X^{2 +}$ ): 20.0 mL
BNeutral medium (to $MnO X_{2}$ ): 33.3 mL
CStrongly alkaline medium (to $MnO X_{4} X^{2 -}$ ): 100.0 mL
DAcidic medium (to $Mn X^{2 +}$ ): 33.3 mL

Answer: A, B, C

Sulphite has n = 2, so 1.00 mmol = 2.00 meq. Normality of permanganate is

0.0200 \times n

: 0.100 N in acid (n = 5), 0.0600 N in neutral medium (n = 3), 0.0200 N in strong alkali (n = 1). Volumes = 2.00/N = 20.0, 33.3 and 100.0 mL respectively. The value 33.3 mL uses n = 3 for acid, so D is wrong. A, B and C are correct.

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1.00 mmol of NaX2​SOX3​ (oxidised to sulphate) is titrated with 0.0200 M KMnOX4​ under different conditions. Which volumes of permanganate solution are required?

Answer: A, B, C

More questions on Redox titration calculations

1.00 mmol of $Na X_{2} SO X_{3}$ (oxidised to sulphate) is titrated with 0.0200 M $KMnO X_{4}$ under different conditions. Which volumes of permanganate solution are required?