Consider the following metallurgical processes :  (1) Heating impure metal with `CO`
Channel: Doubtnut
Date: 2020-07-26

Consider the following metallurgical processes :  (1) Heating impure metal with `CO` and distilling the resulting volatile carbonyl `(BP 43^@ C)` and finally decomposing at `150^@C` to `230^@ C` to get pure metal.  (2) Heating the sulphide ore in air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged sulphide.  (3) Electrolysing the molten electrolyte containing `CaCl_(2)` to obtain the metal  The processes used for obtaining sodium, nickel, and copper are, respectively