What is the starting material for the preparation of $KMnO_4$?

$CoO \cdot Al_2O_3$ is called

When potassium permanganate $(KMnO_4)$ is heated at $513 \ K$,it decomposes to form two manganese-based products. The physical properties of the product in which manganese has a higher oxidation state than the other are:

Which of the following statements regarding copper salts is not true?

On heating potassium permanganate,one of the following compounds is not obtained:

What is the use of potassium dichromate $(K_2Cr_2O_7)$?