CBSE Chemistry Sample Question Paper : Set II
1. Give an example of a photochemical reaction.
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2. An organic component is a constituent of beer, whisky and some cough syrup. It is produced by the fermentation of sugar. Identify the organic compound.
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3. Write the equilibrium constant expression for the following chemical reaction:
N2 (g) + O2 (g) = 2 NO (g) What does a very small value of Kc = 4.8 x 10-31 for this reaction indicate?
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4. Describe with chemical equations, what happens when,
(a) Carbon dioxide gas reacts with ammoniacal brine in Solvay process. (6) Bleaching powder is left exposed to the air containing carbon dioxide gas. © A mixture of finely powdered sand and sodium carbonate is heated in a tank furnace.
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5. Give Chemical tests to:
(a) detect the presence of ethanol.
(b) show that methanal contains an aldehyde group.
© show a saponification reaction.
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6. An organic compound A having molecular formula C2H4O2 reacts with sodium metal and evolves a gas B which readily catches fire. A also reacts with ethanol in the presence of concentrated sulphuric acid to form sweet smelling substance C used in making perfumes.
(a) Identify the compounds A, B and C.
(b) Write balanced chemical equations to represent the conversion of:
(i) Compound A into Compound B (ii) Compound A into Compound C
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7. (a) Explain the role of the following in the extraction of Aluminium from
Bauxite ore: (i) Cryolite. (ii) Inside lining of graphite of the electrolyte tank
(b) Also draw a labelled diagram of the tank used in the electrolytic reduction of Alumina.
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8. Which two metals do not corrode easily? Give an example in each case to support that:
(a) Corrosion of some metals is an advantage.
(b) Corrosion of a metal is serious problem.
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9. (a) Name the sulphur compound present as an impurity in natural gas.
(b) What possible valencies are shown by sulphur in its compounds?
© Draw a labelled diagram of the Frasch process used in the extraction of sulphur.
(a) Why is sulphuric acid called the ‘King of Chemicals’?
(b) Describe with chemical equations how is sulphuric acid manufactured by ‘Contact Process’. © Describe an activity to show that concentrated sulphuric acid is a powerful dehydrating agent.
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