Explain the following
(a) `CO_(2)` is a better reducing agent below 710 K whereas CO is a better reducing agent above 710 K .
(b) Generally sulphide ores are converted into oxides before reduction.
( c) Silica is added to the sulphide ore of copper in the reverberatory furnance.
(d) Carbon and hydrogen are not used as reducing agents at high temperature.
(e) Vapour phase refining method is used for the purification of Ti

Answer

(a) Hint: Use Ellingham diagram
(b) Hint: Oxides are easier to reduce. See Ellingham diagram.
(c) Hint: Sulphide ore of copper contains iron as impurity which is removed as iron silicate (slag)
`FeO + SiO_(2) rarr underset(("Slag"))(FeSiO_(3))`
(d) Hint: carbon and hydrogen react with metals at high temperature to form carbides adn hydrides respectively.
(e) Hint: Ti reacts with iodine to form volatile `TiI_(4)` whcih decomposes at high temperature to give extra pure titanium.