(b) Name one ore of manganese. Which compound of manganese is present in this ore? Also, write its chemical formula.

(c) A zinc ore on heating in air forms sulphur dioxide. Describe briefly any two stages involved in the conversion of this concentrated ore into zinc metal.

Solution:

(a) Copper and silver occur in nature in free states as well as in the combined states.

(b) Pyrolusite; Manganese dioxide; MnO₂.

(c) Roasting and reduction are the two processes required in converting this concentrated ore into zinc metal.
1) Now, roasting is the process of forming zinc oxide and sulphur dioxide from zinc sulphide (zinc blende ore) when it is strongly heated in the air (roasted).
2) Reduction is the process of converting zinc oxide to zinc metal by heating it with carbon. Zinc is extracted from its ore in this manner.