Which of the following methods are not used to refine any metal?
A. Liquation
B. Calcination
C. Electrolysis
D. Leaching
E. Distillation
Choose the correct answer from the options given below:

Solution

Chemistry ma’am · 3 steps

Ask what each method acts on: refining needs crude metal, but calcination and leaching only handle ore.

1. What refining means. Refining is the last step of metallurgy. It takes an impure (crude) metal and removes the remaining impurities. A method counts as refining only if it acts on the metal itself.

   Method	What it acts on	Example	Refining?
   A. Liquation	Crude metal with a low melting point	Sn, Pb, Bi melt and flow away from infusible impurities	Yes
   B. Calcination	Concentrated ore	ZnCO₃ → ZnO + CO₂ on heating	No
   C. Electrolysis	Crude metal used as the anode	Cu, Zn: pure metal deposits on the cathode	Yes
   D. Leaching	Ore, dissolved in a reagent	Bauxite in NaOH, Ag and Au in NaCN	No
   E. Distillation	Crude metal with a low boiling point	Zn, Hg boil off and leave impurities behind	Yes

2. Ore-stage methods. Leaching is a way of concentrating the ore. Calcination turns the concentrated ore into an oxide before reduction. Both happen before any metal has been produced, so they cannot refine a metal.
3. So. Only calcination (B) and leaching (D) are not refining methods. The answer is (a).

The idea to keep. Sort each method by its stage: concentration (leaching, froth flotation), conversion to oxide (calcination, roasting), reduction, then refining. Only methods that act on crude metal count as refining.

Answer from the NTA final answer key. Solution by PrepWiser.