Q82 / 200 · NEET 2003 · Chemistry

The method of zone refining of metals is based on the principle of:

  • A
    greater mobility of the pure metal that than that of the impurity
  • B
    higher melting point of the impurity than that of the pure metal
  • C
    greater noble character of the solid metal than that of the impurity
  • Correct answer
    D
    greater solubility of the impurity in the molten state than in the solid

Solution

The principle of zone refining is that the impurities in ore of metal are more soluble in the melted state when compared to the corresponding solid state of the impurities. In the zone refining process, the impurities are concentrated at one end of the block of metal so that the rest of the block is purified. Related Theory Zone refining process is very effective in the removal of impurities from semiconducting elements such as Germanium, Gallium, and Silicon. This process is also used in refining high-purity metals. Figure

Hence, the correct answer is option: 'D'.

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