Question - 
            
            
            
            
            Answer - 
            The results obtained have been tabulated as follows
   |    Metal    |      Iron(II) sulphate    |      Copper(II) sulphate    |      Zinc sulphate    |      Silver Nitrate    |  
   |    A    |      No reaction    |      Displacement    |      –    |      –    |  
   |    B    |      Displacement    |      –    |      –    |      –    |  
   |    C    |      No reaction    |      No reaction    |      No reaction    |      Displacement    |  
   |    D    |      No reaction    |      No reaction    |      No reaction    |      No reaction    |  
Use the Table above to answer the following questions about metals A, B, C and D.
1.	Which is the most reactive metal?
2.	What would you observe if B is added to a solution of Copper (II) sulphate?
3.	Arrange the metals A, B, C and D in the order of decreasing reactivity.
Answer
(i) Metal B is the most reactive as it gives displacement reaction with iron (II) sulphate.
(ii) When metal B is added to copper (II) sulphate solution, a displacement reaction will take place because of which the blue colour of copper (II) sulphate solution will fade and a red-brown deposit of copper will be formed on metal B.
(iii)Metal B is the most reactive because it displaces iron from its salt solution. Metal A is less reactive because it displaces copper from its salt solution. Metal C is still less reactive because it can displace only silver from its salt solution and metal D is the least reactive because it cannot displace any metal from its salt solution. Hence, the decreasing order of reactivity of the metals is B > A > C > D.