Chemistry - Redox Reactions Question with Solution | TestHub
ChemistryRedox ReactionsTitrationMedium2 minQB
ChemistryMediumnumerical
A sample of is heated strongly in air. The residue left was dissolved in 100 mL of containing dil. . This solution was completely reacted with 50 mL of solution. 25 mL of this solution was completely reduced by 30 mL of solution. Calculate the amount of in g in the sample.
Answer:
1.34
Solution:
30 mL of 0.1 N FeSO₄ = 3 meq reduces 25 mL KMnO₄ ⇒ 1 mL KMnO₄ = 0.12 meq.
So, 50 mL KMnO₄ = 6 meq (total Fe²⁺ left after reaction).
Initial Fe²⁺ taken = 100 mL × 0.1 N = 10 Meq.
Fe²⁺ consumed by Mn₃O₄ = 10 − 6 = 4 Meq.
From stoichiometry: 1 mole Mn3O4 ≡ 2 equivalents ⇒ Meq = 4 ⇒ moles Mn₃O₄ = 0.002 mol.
3 MnSO₄·4H₂O → Mn₃O₄ ⇒ moles MnSO₄·4H₂O = 3 × 0.002 = 0.006 mol.
Mass = 0.006 × 223 = 1.338 g
Stream:JEESubject:ChemistryTopic:Redox ReactionsSubtopic:Titration
⏱ 2mℹ️ Source: QB
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