Dependence of redox reactions on the medium
Answers are for parents and teachers.
1
In neutral medium, how many moles of electrons are accepted by 12 mol of KMnO₄?
36
2
What is the sum of the coefficients in 2KMnO₄ + 3Na₂SO₃ + H₂O = 2MnO₂ + 3Na₂SO₄ + 2KOH?
13
3
What is the sum of the coefficients in 2KMnO₄ + Na₂SO₃ + 2KOH = 2K₂MnO₄ + Na₂SO₄ + H₂O?
9
4
Why does the colour change from orange to green when dichromate reacts with sulfite in acidic medium?
Cr₂O₇²⁻ is reduced to green Cr³⁺ ions.
5
Why is H₂SO₄ rather than HCl used to acidify permanganate?
Permanganate oxidises HCl to Cl₂, so HCl would interfere.