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

Consider the following metallurgical processes in 1. Heating impure metal with CO and distilling the resulting volatile carbonyl boiling point 43^@C and finally decomposing at 150^@ to 200^@C to get the pure metal. II. 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. III. Electrolysing the molten electrolyte containing approximately equal amounts of the metal chloride and CaCl_2 to obtain the metal. The processes used for obtaining sodium, nickel and copper are respectively

Consider the following metallurgical processes : (I) Heating impure metal with CO and distilling the resulting volatile carbonyl (b.p. 43^(@)C) and finally decomposition at 150^(@)-200^(@)C to get the pure metal. (II) 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 metal sulphide. (III) Electrolysis of the molten electrolyte containing approximately equal amounts of the metal chloride and NaCl to obtain the metal. The processes used for obtaining magnesium , nickel and copper are respectively.

Consider the following metallurgical processes : (I) Heating impure metal with CO and distilling the resulting volatile carbonyl (b.p. 43^(@)C) and finally decomposition at 150^(@)-200^(@)C to get the pure metal. (II) 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 metal sulphide. (III) Electrolysis of the molten electrolyte containing approximately equal amounts of the metal chloride and NaCl to obtain the metal. The processes used for obtaining magnesium , nickel and copper are respectively.

Consider the following isolation//purification processes. (I) Heating impure metal with I_(2) at 150 - 200^(@)C and passing the resulting volatile iodide on hot tungsten filament at 1400^(@)C to get the pure metal. (II) 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 metal sulphide to get the metal. (III) Electroysis of the molten electrolyte containing metal oxide and cryolite of fluorspar to obtain the metal. The processes used for obtaining aluminium, titanium and lead are respectively:

Name the process . Ore heated in the absence of air .

The process of heating of ore in the absence of air.