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प्रश्न
Explain: Zone refining
Outline the principles of refining of metals by the following methods
Zone refining
उत्तर
Zone refining: This method is based on the principle that impurities are more soluble in the molten state of metal (the melt) than in the solid state. In the process of zone refining, a circular mobile heater is fixed at one end of a rod of impure metal. As the heater moves, the molten zone of the rod also moves with it. As a result, pure metal crystallizes out of the melt and the impurities pass onto the adjacent molten zone. This process is repeated several times, which leads to the segregation of impurities at one end of the rod. Then, the end with the impurities is cut off. Silicon, boron, gallium, indium etc. can be purified by this process.
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संबंधित प्रश्न
Name the method used for the refining of Nickel metal.
Name the method used for the refining of zirconium.
Name the method of refining of metals such as Germanium.
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
Explain Column chromatography.
What is meant by the term “chromatography”?
What criterion is followed for the selection of the stationary phase in chromatography?
Describe a method for refining nickel.
Write the chemical equations involved in van Arkel method for refining zirconium metal.
Outline the principles behind the refining of metals by the following methods:
Zone refining method
Electrolytic refining is used to purify which of the following metals?
Why is an external emf of more than 2.2 V required for the extraction of \[\ce{Cl2}\] from brine?
How are metals used as semiconductors refined? What is the principle of the method used?
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: Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal.
Reason: Copper is extracted by hydrometallurgy.
Describe a method for refining nickel.
