Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?
(i) Au
(ii) Cu
(iii) Na
(iv) K
(i) and (ii)
(i) and (iii)
(ii) and (iii)
(iii) and (iv)
Answer.:
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In electrolytic refining, electric current is used to purify metals.
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Metals like Cu, Ag, Zn, Au are refined by this method.
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Na, K, and Ca cannot be refined using electrolysis because they are highly reactive. They are refined by electrolytic reduction instead.
