Question

On addition of small amount of KMnO₄ to concentrated H₂SO₄, a green oily compound is obtained which is highly explosive in nature. Identify the compound from the following.
(a) Mn₂O₇
(b) MnO₂
(c) MnSO₄
(d) Mn₂O₃

Answer 1

(a) Mn₂O₇

2KMnO₄ + H₂SO₄ → Mn₂O₇ + H₂O + K₂SO₄

Here, When Potassium permanganate is dissolved in concentrated Sulphuric acid, a green colored Manganese heptoxide (Mn₂O₇) is obtained.

This manganese heptoxide is highly explosive in nature.

Further reaction, by internal thermal decomposition-

2Mn₂O₇ → 4MnO₂ + 3O₂