(a) Name an ore of zinc

(b) Which process is applied to concentrate it?

(c) How is concentrated ore changed to oxide?

(a) Zinc blende, chemical name is Zinc sulphide and formula is ZnS.

(b) Froth floatation process is applied to concentrate ZnS.

(c) The concentrated ore is changed to oxide by heating Zinc blende (ZnS) in excess of air. The reaction is as follows:

$2\text{ZnS} + 3\text{O}2 \xrightarrow{800 \degree\text{C}} \text{2ZnO} + \text{2SO}_\text{2}$