CBSE Chemistry Model Test Paper : Set III
1. What are endothermic reactions? Give one example of an endothermic reaction.
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2. Write the equation for the reaction which takes place when sodium oxide reacts with water.
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3. What is Plaster of Paris? How is it obtained?
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4. (a) Define pH of a solution.
(b) Determine the pH of 0.005 M sulphuric acid.
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5. Explain the following terms: (a) Mortar
(b) Concrete.
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6. (a) How is propanone prepared commercially? Give the reactions involved in it. (b) What is the advantage of using vulcanised rubber over natural rubber?
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7. A non-metal belonging to group 16 of the periodic table is mined by a special technique based on its low melting point. Identify the non-metal and name the process by which it is extracted. With the help of a labelled diagram, explain the method of its extraction.
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8. What would you observe when sulphur dioxide is passed through (a) lime water,
(b) acidified potassium dichromate solution?
Write the chemical reactions that take place.
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9. Write a reaction to show the
(a) addition of HCN to methanal.
(b) oxidation of methanal by Fehling’s reagent.
© oxidation of ethanol by CrO3 in CH3COOH.
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10. (a) Draw a flow chart for the manufacture of ammonia by Haber process.
(b) (i) How will you separate hydrogen from a mixture of carbon dioxide and hydrogen?
{ii) How is granulated zinc prepared? Why is it preferred over metallic zinc for the preparation of hydrogen gas in the laboratory.
(a) Draw a labelled diagram of the apparatus which could be used to purify a block of impure copper.
(b) Aluminium oxide is an amphoteric oxide. Explain what is meant by amphoteric.
© (i) Write a chemical equation for the reaction between methane and steam.
(ii) Vegetable ghee is manufactured by the reaction between hydrogen and vegetable oils in the presence of a catalyst. What types of bonds must be present in the vegetable oil for this reaction to take place?
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