Question

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

• A. (i) and (ii)
• B. (i) and (iii)
• C. (ii) and (iii)
• D. (iii) and (iv)

Answer 1

The correct option is A

(i) and (ii)

The explanation for Correct answer:

Option A (i) and (ii)

• The metals obtained by various reduction processes are not very pure.
• They contain impurities that must be eliminated before pure metals can be obtained.
• Impurities such as Gold, Silver, Platinum group metals, Arsenic, Selenium, and Tellurium can be recovered by the electrolytic refining method.
• Electrolytic refining is a technique that is used for the extraction and purification of metals that are obtained by refining methods.
• The impure metal is used as an anode and the pure metal is used as a cathode.
• Soluble salt from the same metal can be used as an electrolyte.
• When an electric current is passed, pure metal gets deposited at the cathode, and the impure metal gets dissolved from the anode.
• Impurities from the metal get collected below the anode and are known as anode mud.
• The most widely used method for refining impure metals and metals such as Copper and Gold is refined electrolytically.
• Hence Option A (i) and (ii) is correct.

The explanation for incorrect answers:

Option B (i) and (iii)

• Sodium is a highly reactive metal and is extracted by the electrolytic reduction of their molten chloride salts.
• In this process, the ionic substances are decomposed into simpler substances when an electric current is passed through them.
• Gold is extracted by electrolytic refining which is used to obtain pure metals.
• Hence Option B (i) and (iii) is incorrect

Option C (ii) and (iii)

• Sodium is a highly reactive metal and is extracted by the electrolytic reduction of molten chloride salts.
• Copper is extracted by electrolytic refining which is used to obtain pure metals.
• Hence Option B (ii) and (iii) is incorrect

Option D (iii) and (iv)

• Sodium and potassium are highly reactive metals and are extracted by the electrolytic reduction of molten chloride salts.
• Hence Option D (iii) and (iv) is incorrect.