In a science fair , a student took two test tubes labelled A and B filled with copper sulphate solution, then he put magnesium ribbon in test tube A silver foil in tube B. Predict the observation and justify.

Explanation

`{:("A","B"),(CuSO_(4),CuSO_(4)),(+,+),(Mg,Ag),(darr,darr),(MgSO_(4)+Cu,"No reaction"):}`
The blue coloured `CuSO_(4)` solution in test tube 'A' disappears and thus colourless sloution of `MgSO_(4)` is formed .this is due to higher reactivity of Mg than Cu . Hence Mg can displace Cu from `CuSO_(4)` solution and hence blue coloured `CuSO_(4)` slowly turns colourless .Ag being less reactive than Cu, cannot displace Cu from `CuSO_(4)` and hence the solution remains blue.