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प्रश्न
Explain:
Zone refining
Outline the principles of refining of metals by the following method:
Zone refining
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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.
संबंधित प्रश्न
Name the method used for the refining of Nickel metal.
What is the principle behind the zone refining of metals?
What is meant by the term “chromatography”?
Out of PbS and PbCO3 (ores of lead), which one is concentrated by froth floatation process preferably?
Indicate the principle behind the method used for the refining of Nickel.
Outline the principles behind the refining of metals by the following methods:
Zone refining method
What happens when NaCN is added in an ore containing PbS and ZnS during concentration by froth floatation method?
Electrolytic refining is used to purify which of the following metals?
In which of the following method of purification, metal is converted to its volatile compound which is decomposed to give pure metal?
(i) Heating with stream of carbon monoxide.
(ii) Heating with iodine.
(iii) Liquation.
(iv) Distillation.
In the extraction of chlorine from brine:
(i) ∆GΘ for the overall reaction is negative.
(ii) ∆GΘ for the overall reaction is positive.
(iii) EΘ for overall reaction has negative value.
(iv) EΘ for overall reaction has positive value.
Which one of the following methods can be used to obtain highly pure metal which is liquid at room temperature?
Describe a method for refining nickel.
Describe a method for refining nickel.
Describe a method for refining nickel.
Describe a method for refining nickel.
Describe a method for refining nickel.
Describe a method for refining nickel.
Describe a method for refining nickel.
