CBSE Chemistry Model Test Paper : Set IV
1. State whether an aqueous solution of washing soda is acidic or alkaline. How will you prove it?
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2. Give an example of a non-metal which
(a) has a shiny appearance just like metals,
(b) conducts electricity.
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3. Why are metals reducing agents whereas non-metals are oxidising agents?
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4. What is meant by the term metallurgy? Name its three steps.
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5. A sanitary worker uses a white substance having a strong smell of chlorine to clean a water tank. Identify the substance. How is it prepared? Write the equation of the chemical reaction for its preparation.
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6. (a) Explain the difference between average reaction rate and instantaneous reaction rate.
(b) What is the effect of temperature on the
(a) rate of a reaction.
(b) concentration of product(s) at equilibrium of an endothermic reaction carried out in a closed container?
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7. What are soaps and detergents? Explain the mechanism of the cleansing action of soaps.
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8. Write an equation for the reaction when
(a) sodium acetate is heated with soda-lime.
(b) ethanol reacts with ethanoic acid in presence of cone. H2SO4.
© ethene reacts with water in presence of sulphuric acid.
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9. What is bauxite? What are the main impurities that are found in this ore? Briefly describe how the ore is purified.
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10. (a) Describe briefly the action of heat on sulphur. (6) Write a reaction to show
(i) the reducing action of hydrogen,
(ii) the dehydrating action of cone. H2 SO4 on sugar.
(iii) the catalytic oxidation of ammonia to nitric oxide.
(a) Describe an activity to show that hydrogen is lighter than air.
(b) Choose from the following gases to answer the questions below: ammonia, carbon dioxide, hydrogen, nitrogen, oxygen, sulphur dioxide. Each gas can be used once, more than once or not at all. Name a gas which (i) is used to bleach wood pulp.
(ii) is used in the manufacture of fertilizers.
(iii) could be developed as an alternative fuel for the future.
(iv) changes acidified potassium dichromate from orange to green.
(v) is evolved at the anode during the electrolysis of alumina dissolved in
cryolite.
(vi) is evolved when ammonia is passed over heated copper(II) oxide.
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