Question

Why can metals high up in the reactivity series not be obtained by reduction of their oxides by carbon ?

Name the ore of mercury and state the form in which it is found in nature. Write the chemical equations along with the condition required for the reactions involved in the extraction of mercury from its ore.

Assertion (A) : The extraction of metals from their sulphide ores cannot take place without roasting of the ore. Reason (R) : Roasting converts sulphide ores directly into metals.

Assertion (A) : Metals in the middle of activity series are found in nature as sulphides or carbonates. Reason (R) : The sulphide ores are calcinated whereas carbonate ores are roasted to extract metals from them.

(a) "Displacement reactions also play a key role in extracting metals in the middle of the reactivity series." Justify this statement with two examples. (b) Why can metals high up in the reactivity series not be obtained by reduction of their oxides by carbon ?