Question

Why is KMnO, not regarded as a primary standard?​

Answer 1

Answer:Potassium permanganate is not a primary standard, and preparation of the solution will always cause formation of solid manganese dioxide (MnO2). ... Potassium permanganate solutions are unstable, and must also be filtered after long periods of storage, because manganese dioxide (MnO2) will precipitate out during storage.

Explanation:

Answer 2

Answer:

Because of its intense colour, the ion serves as its own indicator, so there is no need to add an indicator as is usually required. Potassium permanganate is not a primary standard, and preparation of the solution will always cause formation of solid manganese dioxide (MnO2).