Question

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

The metals produced by various reduction processes are not very pure. They contain impurities, which must be removed to obtain pure metals. The most widely used method for refining impure metals is electrolytic refining.

Identify the product 'X' obtained in the following chemical reaction : CaCO₃ —Δ→ 'X' + CO₂

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.