3) To observe the action of Zn, Fe, Cu and Al metals on the following salt solutions
Aim
(i) To observe the action of Zn, Fe, Cu and Al metals on the following salt solutions:
(a) ZnSO4(aq.)
(b) FeSO4(aq.)
(c) CuSO4 (aq.)
(d) Al2(SO4)3(aq.)
(ii) Arrange Zn, Fe, Cu and Al metals in the decreasing order of reactivity based on the above result.
Theory
> Reactivity series: The arrangement of metals in decreasing order of their reactivity is called reactivity series. The most reactive metal displaces the less reactive metal from its salt solution.
> Metal salts are coloured
> Reaction of Metals with Salt Solution
(i) Salt solution CuSO4.
As Al, Zn and Fe can displace Cu from its salt solution hence, all three are more reactive than Cu.
(ii) Salt solution FeSO4.
As Zn and Al can displace Fe from its salt solution hence, Zn and A1 are more reactive than Fe but Cu is less reactive than Fe.
(iii) Salt solution ZnSO4.
As only Al metal displaces Zn from its salt solution hence, Al is the most reactive metal among Al, Zn, Fe and Cu.
Al > Zn > Fe > Cu.
Materials Required
Four clean test tubes, marker, a piece of sand paper and test tube stand.
Chemicals required: Aluminium sulphate solution, copper sulphate solution, zinc sulphate solution, iron sulphate solution, metal strips of iron, zinc; copper and aluminium.
Procedure
> Reaction with CuSO4 solution:
1. Take four clean test tubes.
2. With a marker label them as A, B, C and D.
3. Take copper sulphate solution in each test tube.
4. Dip a small, clean piece of aluminium, zinc, iron and copper metals in test tubes A, B, C and D respectively.
5. Record your observations.
Conclusion: Al, Zn and Fe metals are more reactive than Cu. Hence, Cu is the least reactive metal among the given four metals.
> Reaction with FeSO4 solution:
1. Take four clean test tubes, labelled as A, B, C, and D.
2. Take FeSO4 (aq) solution in each test tube.
3. Dip small, clean pieces of aluminium, zinc, iron and copper metals in test tube A, B, C and D respectively.
4. Record your observations.
Conclusion: Al and Zn metals are more reactive than Fe and Cu.
> Reaction with ZnSO4 solution:
1. Take test tubes A, B, C, and D, clean them.
2. Add ZnSO4 solution in each test tube.
3. Dip small, clean pieces of Al, Zn, Fe and Cu metal in test tube A, B, C and D respectively.
4. Record your observations.
Conclusion: Al metal is more reactive than Zn metal.
> Reaction with Al2(SO4)3 solution:
1. Take test tubes A, B, C, and D and clean them.
2. Add Al2(SO4)3 solution in each test tube.
3. Dip small, clean pieces of Al, Zn, Fe and Cu metal in test tubes A, B, C and D respectively.
4. Record your observations.
Conclusion: Al metal is not displaced by any of the given metals i.e. Al, Zn, Fe and Cu.
Hence, Al metal is the most reactive metal among the given metals.
1. Al is not displaced by any of the four metals from its salt solution, hence, Al is at the top of the reactivity series.
2. Al can displace Zn from its salt solution but no other metal could displace it. Hence, the reactivity order is Al > Zn.
3. Al and Zn metals can displace Fe metal from its salt solution but Cu cannot.
Hence, the arrangement of metals in decreasing reactivity order is
Al > Zn > Fe > Cu.
I. CuSO4 solution in each test tube.
II. FeSO4 solution in each test tube.
III. ZnSO4 solution in each test tube.
IV. Al2(SO4)3 solution in each test tube.
Precautions
1. Clean the metals by rubbing them with a piece of sand paper before dipping them in the salt solutions.
2. Wash the test tubes after every set of observations of interaction of a particular metal with the four salt solution.
3. Use very little amount of saturated solution of copper sulphate, aluminium sulphate, iron sulphate and zinc sulphate.
4. Use very small pieces of metal every time.
5. Do not touch any chemical.
