Q39 of 65 Page 24

Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?

Extraction of a metal from its oxide is easier as compared to its extraction from its sulphides and carbonates. Metals occur in the form of its ores. An ore is a mineral from which metal can be extracted. Ores found in the form of carbonates and sulphides are first converted into their oxides by the process of calcination and roasting. Oxides thus obtained are converted to metals by the process of reduction. Later metals are purified by various purification methods.


More from this chapter

All 65 →
37

Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how he can identify the produced gas. Write chemical equations for both the reactions.

 38

During extraction of metals, electrolytic refining is used to obtain pure metals. (a) Which material will be used as anode and cathode for refining of silver metal by this process? (b) Suggest a suitable electrolyte also. (c) In this electrolytic cell, where do we get pure silver after passing electric current?

 40

Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?

 41

Compound X and aluminium are used to join railway tracks. (a) Identify the compound X (b) Name the reaction (c) Write down its reaction.