Question

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.

Hint:

The reactivity of metals can be determined by observing whether they displace other metals from their solutions. More reactive metals displace less reactive ones.

Answer 1

(i) Least reactive metal: Metal D is the least reactive since it does not displace any metal from any solution (it shows no reaction). 
(ii) Observation when C is added to copper sulphate: C will not displace copper from copper sulphate as indicated by the table; thus, no visible change is expected. 
(iii) Order of decreasing reactivity: A>B>C>D. This is based on the results of the displacement reactions, with A being the most reactive and D being the least reactive.