Class 11 Chemistry Notes Stocihiometry – Important Question Answers

Ex.  A volume of 12.53 ml of 0.051 M SeO₂ reacts exactly with 25.5 ml of 0.1 M CrSO₄ which is oxidized to Cr³⁺ To what oxidation state was the selenium converted b the reaction.

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Ex. In basic solution CrO₄^2- ion oxidizes S₂O₃^2- ion to form Cr(OH)₄^– and SO₄^2- ions respectively. How many ml of 0.154 Na₂CrO₄ solutions are required just to react with 40 ml of 0.246 M Na₂S₂ O₃ solutions.

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Ex. What mass of N₂H₄ can be oxidized to N₂ by 24 gm of K₂CrO₄ which is reduced to

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Ex. The ion Aⁿ⁺ is oxidized to AO₃^– by MnO₄^– changing to Mn²⁺ in acid medium. Given that mole of Aⁿ⁺ required  mole of MnO₄^–. What is the value of n.

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Ex. 25 ml of 0.17 M HSO₃^– in strongly acidic solution required the addition of 16.9 ml of 0.01 M MnO₄^– for its complete oxidation to SO₄^2-. In neutral solution it requires 28.6 ml. Assign oxidation no. of ‘Mn’ in each of the products.

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Ex. A given amount of Fe²⁺ is oxidized by x mol of MnO₄^– in acidic medium. Calculate mol of Cr₂O₇^2- required same amount of Fe²⁺ in acidic medium

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Ex. Calculate mol of (a) MnO₄^– and (b) Cr₂O₇^2- to oxidize 1 mol of FeC₂O₄ (ferrous oxalate) in acidic medium.

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Ex. A mixture of Na₂C₂O₄ and KHC₂O₄. H₂C₂O₄ required equal volume of 0.1 M KMnO₄ and 0.1 M NaOH separately. What is the molar ratio of Na₂C₂O₄, KHC2O4 and H₂C₂O₄ in the mixture?

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Ex. 5.5 gm of a mixture of FeSO₄. 7H₂O and Fe₂ (SO₄)₃. 9H₂O requires 5.4 ml of 0.1 N KMnO₄ solutions for complete oxidation. Calculate the no. of gm moles of hydrated ferric sulphate in the mixture?

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