Page 2 - H. A.-2 (Practice WS-7)

Subjective-
Q.6.The reaction of metal X with Fe2O3 is highly exothermic and is used to join railway
tracks. Identify metal X. Write the balanced chemical equation for the reaction.
[ A+Av ] (3mark) [CBSE 2016]

Q.7.Out of the two metals P and Q, P is less reactive than Q. Suggest an activity to
arrange these metals in the order of decreasing reactivity. Support your answer with a
suitable chemical equation. [ A+D ] (3mark) [CBSE 2014]

Q.8 Using the electronic configuration, explain how magnesium atom combines with
oxygen atom to form magnesium oxide by transfer of electrons. [ A+Av ] (3mark)
[CBSE 2011]

Q.9. Explain the following statements: [ A+Av ] (3mark) [CBSE 2016]
a. Most metal oxides are insoluble in water but some of these dissolve in water. What
are these oxides and their solution in water called?

b. At ordinary temperature the surface of metals such as magnesium, aluminium, zinc
etc. is covered with a thin layer. What is the composition of this layer? State its
importance.

c. Name two alkali metals can be cut with knife.

Q10. Four metals A, B, C and D are added to the following aqueous solutions one by
one. The observations made are tabulated below: [ A+D] (5mark)

Iron Copper Sulphate(II) Zinc Sulphate Silver Nitrate
(II)Sulphate
A No Reaction Reddish brown deposit .......
B Grey Deposit ...... No Reaction ...............
C No Reaction No Reaction No Reaction White shining
deposit
D No Reaction No Reaction No Reaction No Reaction

Answer the following questions based on the above observations:

a.Which is the most active metal and why?
b.What would be observed if B is added to copper(II) sulphate solution and why?
c. Arrange the metals A, B, C and D in order of increasing reactivity.
d.Container of which metal can be used to store both zinc sulphate solution as well as
silver nitrate solution?
e. Which of the above solutions can be easily stored in a container made up of any of
these metals?
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