Manganese
Answers are for parents and teachers.
1
Write the reduction products of KMnO₄ in acidic, neutral and alkaline medium.
Acidic — Mn²⁺; neutral — MnO₂; alkaline — MnO₄²⁻ (K₂MnO₄).
2
How many grams of Mn are obtained by reducing 458 g of Mn₃O₄ with aluminium? (3Mn₃O₄ + 8Al → 9Mn + 4Al₂O₃; M(Mn₃O₄) = 229, A(Mn) = 55)
330
3
In 2KMnO₄ + 5K₂SO₃ + 3H₂SO₄ → ..., how many moles of electrons do 2 mol of KMnO₄ accept?
10
4
Write the equations of Mn + HCl and Mn + H₂O (on heating).
Mn + 2HCl → MnCl₂ + H₂↑; Mn + 2H₂O → Mn(OH)₂ + H₂↑.
5
Why must KMnO₄ not be stored together with combustible substances?
It is a strong oxidiser and can cause fire or explosion with combustible substances.