Zinc is refined by (a) liquation (or) distillation under reduced pressure (b) electrolytic method or polling (c) liquation or electrolytic method (d) distillation under reduced pressure or electrolytic method

To select the most correct method used in zinc refining, understanding the key terms is the first step: 1. Liquation: A method of refining metals where the metal is heated to a temperature above its melting point and then allowed to flow out of the furnace. 2. Distillation under Reduced Pressure: This method involves the evaporation and subsequent collection of a liquid by condensation as a means of purification. 3. Electrolytic Method: This is a process that uses electrical energy to drive an otherwise non-spontaneous reaction. It is most often used to separate chemically combined elements within an ionic compound. 4. Polling: This method is used to refine metals with a high boiling point. In this process, green wood is stirred into the molten metal. The gases produced by the wood being burned make the metal frothy and take the impurities to the surface.

Now, let's analyze the given options in relation to zinc refining: (a) Zinc refining does not typically involve either liquation or distillation under reduced pressure. (b) Electrolytic methods can be used for refining zinc, but polling is typically not involved in the process of refining this particular metal. (c) While electrolytic methods are used for zinc refining, liquation is typically not involved. (d) Zinc is not typically refined through distillation under reduced pressure, but electrolytic methods are used.

By considering the details outlined above, the correct option seems to be (c) which mentions the electrolytic method as one of the processes employed in zinc refining. Although it mentions liquation, from the given choices, this is the closest correct answer. Thus, the answer to the exercise is (c) liquation or electrolytic method.