Question

Pieces of four metals A,B,C & D were one by one added to four solutions, namely Fe(II)SO4, Cu(II)SO4, ZnSO4 and AgNO3.The observations are tabulated below:
METAL:Fe(II)SO4 Cu(II)SO4 ZSO4 AgNO3
A No react Displacemnt - -
B Displacmnt - No react -
C - - No react Dsplacmnt
D - - No react No react
a) Which is the most active metal and why?
b)What is observd if B is added to CuSO4 and why?
c)Arrange metals A,B,C,D in increase reactivity

Answer 1

A metal can displace another metal from a solution if the first metal is more reactive than the second.

Metal A can displace Cu but cannot displace Fe
=> A is more reactive than Cu but less reactive than Fe
Fe > A > Cu --- (1)

B displaced Fe but couldnt displace Zn
=> Zn > B > Fe --- (2)

C displaced Ag but couldnt displace Cu
=> Cu > C > Ag --- (3)

D couldnt displace Cu or Ag
=> Ag > D --- (4)

Combine (1), (2), (3), (4) to get
Zn > B > Fe > A > Cu > C > Ag > D
This is the reactivity series

Thus the most active metal among A,B,C,D is B.
B is more reactive than Cu, thus it will displace Cu from CuSO4

Answer 2

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