Identify the correctly matched pairs:
$(i)$ $TiO_2$ - pigment industry
$(ii)$ $MnO_2$ - dry battery cells
$(iii)$ $Cu/Ni$ alloy - $UK$ 'copper' coins

The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products $A$ and $B$ along with the evolution of $CO_2$. The sum of spin-only magnetic moment values of $A$ and $B$ is .......... $B.M.$ (Nearest integer)
(Given atomic number: $C: 6, Na: 11, O: 8, Fe: 26, Cr: 24$)

Generally,metal ions and their salts are coloured due to the presence of unpaired electrons in the metal ions. Which of the following compounds is coloured?

Which of the following is used in the manufacture of high refractive index optical glass for cameras?

Identify the statement which is not correct regarding copper sulphate.

$KMnO_4$ decomposes on heating at $513 \ K$ to form $O_2$ along with