JEE Main · 2020 · 05 Sep 2020 · Shift 2 · General Principles and Processes of Isolation of Metals

Boron and silicon of very high purity can be obtained through:

(A)zone refining✓ Correct
(B)electrolytic refining
(C)liquation
(D)vapour phase refining

Answer: (A)

Solution

Semiconducting elements such as boron and silicon are purified by zone refining, which uses the fact that impurities prefer the molten phase. A heater melts a narrow band and is drawn slowly along the rod, carrying the impurities to one end and leaving behind the ultra-high-purity material these elements require.

JEE Main · 2020 · 05 Sep 2020 · Shift 2 · Single correct option

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