Describe a method for refining nickel.

लघु उत्तरीय

Mond’s process refines nickel. In this process, nickel is heated in the presence of carbon monoxide to form nickel tetracarbonyl, a volatile complex.

\[\ce{Ni + 4 CO ->[330 - 350 K] \underset{Nickel tetracarbonyl}{Ni(CO)4}}\]

Then, the obtained nickel tetracarbonyl is decomposed by subjecting it to a higher temperature (450-470 K) to obtain pure nickel metal.

\[\ce{\underset{tetracarbonyl}{\underset{Nickel}{Ni(CO)4}} ->[450-470 K] \underset{Nickel}{Ni} + 4CO}\]

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क्या इस प्रश्न या उत्तर में कोई त्रुटि है?

Explain the principle of the method of electrolytic refining of metals. Give one example.

Describe the roles of the following: NaCN in froth floatation process

Outline the principles behind the refining of metals by the following methods:

Chromatographic method

Write the principle behind the following methods of refining:

Vapour-phase refining

What happens when Silver is leached with NaCN in the presence of air?

Match the items of Column I with the items of Column II and assign the correct code:

Column I	Column II
(A) Coloured bands	(1) Zone refining
(B) Impure metal to volatile complex	(2) Fractional distillation
(C) Purification of Ge and Si	(3) Mond Process
(D) Purification of mercury	(4) Chromatography
	(5) Liquation

Assertion: Nickel can be purified by Mond process.

Reason: \[\ce{Ni(CO)4}\] is a volatile compound which decomposes at 460 K to give pure Ni.

Assertion: Zirconium can be purificed by Van Arkel method.

Reason: ZrI₄ is volatile and decomposes at 1800 K.

Assertion: Zone refining method is very useful for producing semiconductors.

Reason: Semiconductors are of high purity.

Assertion: Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal.

Reason: Copper is extracted by hydrometallurgy.

Purification of crude metals by removing metallic and non-metallic impurities is known as ______ of metals.

Describe a method for refining nickel.