Explain the following
1. is a better reducing agent below 710 K whereas CO is a better reducing agent above 710 K.
2. Generally sulphide ores are converted into oxides before reduction.
3. Silica is added to the sulphide ore of copper in the reverberatory furnace.
4. Carbon and hydrogen are not used as reducing agents at high temperatures.
5. Vapour phase refining method is used for the purification of Ti.