Question

A. How many mL of a 0.118 M solution of KMnO₄ are needed to titrate 20.0 mL of 0.214 M solution of sodium oxalate, Na₂C₂O₄? The net ionic equation is 2MnO₄^-(aq) + 5C₂O₄^2-(aq) +16H⁺(aq) → 2Mn²⁺(aq) + 10CO₂(g) + 8H₂O(l)

B. In which of the following compounds can an element highlighted in red act as an oxidizing agent? CaH₂, CH₄, NH₃, ClO₂, H₂O

Answer 1

A) according to balanced reaction

Na2C2O4 and KMnO4 reacts in 5 : 2 ratio

millimoles of Na2C2O4 = 20.0 x 0.214 = 4.28

according to balanced reaction

5 moles oxalate reacts with 2 moles permanganate

4.28 moles oxalate reacts with 4.28 x 2 / 5 = 1.712 millimoles MnO4^-

1.712 = V x 0.118

V = 14.51 mL

volume of KMnO4 required = 14.51 mL

B) answer = ClO2

in ClO2

Cl = +4 oxidation state

so Cl can reduce by gaining electrons .

species which can reduce act as oxidizing agent.