M.C.Q
Objective: a) To observe the action of Zn, Fe, Cu and Al
metals on the following salt solutions:
(i)
ZnSO4(aq)
(ii)
FeSO4(aq)
(iii) CuSO4(aq)
(iv)
Al2(SO4)3(aq)
b) Arrange Zn, Fe, Cu and Al metals in the
decreasing order of reactivity based on the
above result.
1. A piece of granulated Zn was dropped into copper sulphate solution. After
some time the colour of the solution changed from
a> Light green to blue
b> Blue to colourless
c> Light green to colourless
d> Blue to green
2. When an Aluminium strip is kept immersed in freshly prepared Ferrous
sulphate solution taken in a test tube, the change which is observed is
a> The green solution turns brown
b> The lower end of the test tube becomes slightly warm.
c> A colourless gas with smell of burning sulphur is observed.
d> Light green solution changes to blue.
3. A student performed the following displacement reaction :
Fe(s) + CuSO4(aq)→ FeSO4(aq) + Cu(s)
Zn(s) + FeSo4(aq)→ ZnSO4(aq) + Fe(s)
2Al(s) + 3ZnSO4(aq) →Al2(SO4)3(aq) + 3Zn(s)
Arrange Fe, Zn, Al, Cu, in the decreasing order of reactivity on the basis of
above reaction
a> Al>Zn>Fe>Cu
b> Fe>Cu>Zn>Al
c> Zn>Cu>Fe>Al
d> Al>Zn>Cu>Fe
4. To show that the zinc is a more active metal then copper, the correct procedure
is to :
a> Add dilute nitric acid on strips of both the metals.
b> Observe transmission of heat through strips of zinc and copper.
c> Prepare solution of zinc sulphate and hang strip of copper into it.
d> Prepare solution of copper sulphate and hand strip of zinc into it.
5. A student prepares an aqueous solution of CuSO4 in beaker ‘X’ and an
aqueous solution of FeSO4 in beaker ‘Y’. He then dropped some iron pieces in
beaker ‘X’ and zinc pieces in beaker ‘Y’. After about 10 hours he observed
that the solution in X and Y respectively appear:
a> Blue and green
b> Colourless and pale green
c> Colourless and light blue
d> Greenish and colourless
6. An iron nail was kept immersed in aluminium sulphate solution. After about
an hour, it was observed that
a> The colourless solution changed to light green
b> The solution became warm
c> Grey metal was deposited on the iron nail
d> The solution remained colourless and no deposition was observed on iron
nail
7. A cleaned aluminium foil was placed in an aqueous solution of zinc sulphate.
When the aluminium foil was taken out of the zinc sulphate solution after 15
minutes, its surface was found to be coated with a silvery grey deposit. From
the above observation it can be concluded that:
a> Aluminium is more reactive than zinc.
b> Zinc is more reactive than aluminium.
c> Zinc and aluminium both are equally reactive.
d> Zinc and aluminium both are non-reactive.
8. Solution of copper sulphate, iron sulphate and zinc sulphate are prepared and
marked I, II and III respectively. Few pieces of aluminium are added to each
solution. After sometime a change will be observed in
a> I and II
b> II and III
c> III and I
d> All the three
9. Two beakers A and B contain Iron (II) sulphate solution. In the beaker A a
small pieces of copper is placed and in the beaker B a small pieces of zinc is
placed. It is found that a grey deposit forms of the zinc but not the copper.
From this observation it can be conclude that
a> Zinc is most active metal followed by iron and copper
b> Zinc is most active metal followed by copper and then iron
c> Iron is most active metal followed by zinc and then copper
d> Iron is most active metal followed by copper and then zinc
10. The colours of aqueous solution of CuSO4 and FeSO4 as observed in the
laboratory are :
a> Pale green and light blue respectively
b> Light blue and dark green respectively
c> Dark blue and dark green respectively
d> Dark blue and pale green respectively