Poling is a process used in the refining (purification) of metals, particularly copper and tin. In this process, green wood logs are used to stir the molten metal. The hydrocarbons in the wood reduce the metal oxide impurities present in the metal, thus purifying the crude metal.
Samples of four metals A, B, C, and D were added one by one to the following solutions. The results obtained were tabulated as follows:
Use the table above to answer the following questions about metals A, B, C, and D:
(i) Which is the least reactive metal?
(ii) What would be observed if C is added to a solution of copper sulphate?
(iii) Arrange the metals A, B, C, and D in the order of their decreasing reactivity.