Describe how the following changes are brought about:
(i)Pig iron into steel.
(ii)Zinc oxide into metallic zinc.
(iii)Impure titanium into pure titanium.

Explanation

(i) Pig iron is converted into steel by adding carbon and some other elements.
(ii) Metallic Zinc is obtained from zinc oxide by reduction with coke.
`ZNO+C overset("Heat")to Zn+CO`
(iii)Impure titanium is heated with Iodine toform volatile complex TiI_(4) which on furtherheating to higher temperature decomposes to give pure titanium.