Question

Give reasons for the following:

(a) Gold and silver are used for jewellery making
(b) carbonate and sulphide ores are usually converted into oxides prior to reduction during the process of extraction
(c) Aluminium oxide is considered as an amphoteric oxide​

Answer 1

A) Platinum, gold and silver are used to make jewellery because the metals used in jewellery are always be chosen on the basis of its reactivity. ... They are highly lustrous metals which are resistant to corrosion. They are highly malleable and ductile so can be transformed into any shape or design.

B) Carbonate and sulphide ores are usually converted into oxides during the process of extraction. Why? Answer: Obtaining a metal from its oxide is much easier than doing that from a metal sulphide or carbonate. Due to this; metal sulphides and carbonates are first converted to metal oxides during metallurgy.

C) Aluminum Oxide

Aluminium oxide is amphoteric. It has reactions as both a base and an acid. Reaction with water: Aluminum oxide is insoluble in water and does not react like sodium oxide and magnesium oxide. The oxide ions are held too strongly in the solid lattice to react with the water.