The starting material for the manufacture of $KMnO_4$ is

Indicate the steps in the preparation of:
$(i)$ $K_2Cr_2O_7$ from chromite ore.
$(ii)$ $KMnO_4$ from pyrolusite ore.

The spin-only magnetic moment value of the most basic oxide of vanadium among $V_2O_3$,$V_2O_4$,and $V_2O_5$ is $..... \ B.M.$ (Nearest Integer).

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:

Provide the structures for:
$1.$ $MnO_4^{-}$
$2.$ $MnO_4^{2-}$

Zinc forms two important alloys,$(i)$ Brass and $(ii)$ German silver. Metals present in them mainly are