» CBSE Science Practice Paper : Set V : CBSE Sample Question Papers

16. How will you prepare ammonia gas in the laboratory ? Draw a labelled diagram and write the chemical reaction involved. Give one chemical test for detecting presence of NH~ gas. 3
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17. Complete the following reactions :

(i) CH₃COOC₂H₅+NaOH—————>
(ii) CH₃CH₂OH
CrO₃in/CH₃COOH

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18. (i) What is Myopia ? How can you correct it ? Draw diagrams to show defective and corrected eye. (ii) A short sighted person cannot see objects beyond 100 cm. How can you correct it to enable him to see an object at 150 cm ?

OR
(i) What is Hypermetropia ? How can you correct it ? Draw diagrams to show defective and corrective
eye.
(ii) A farsighted woman has a near point of 1.5 m. Calculate the focal length of the lenses for her eye glasses, so that she can read a book held at 25 cm. 3+2
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19. What is meant by refining of metals ? Explain three processes for refining of metals. Which method is used for refining volatile metals ?

OR
{a) What are non-metals ? Give two physical and two chemical properties of non-metals. (b) What happens when
(i) Hydrogen reacts with heated CuO ;
(ii) Sulphur dioxide reacts with lime water. 5
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20. How can we extract aluminium metal from Bauxite ore. Explain purification of bauxite with the help of chemical reactions and extraction with the help of neat and labelled diagram. 5
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Section - B

21. Name the gland which produces (a) FSH. (b) Oxytocin. 1
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22. Give two examples of organisms which can regenerate from small part of their body. 1
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23. What are analogous organs ? Give one example. 1
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24. What do you mean by National Parks and Sanctuaries ? 2
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25. Define heart beat and heart sound. 2
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26. Discuss the importance of vegetative propagation.

OR
‘Grafting is a common method of obtaining a superior plant from two different plants’ ? Explain. 3
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27. Write note on ‘Chemical Control in Animals’. 3
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28. What do you mean by water table ? What happens if water table in a region falls ? 3
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29. Differentiate between lymphatic capillaries and blood capillaries. 3
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30. Explain with a diagram the structure of a chromosome. Write the features of eukaryotic and prokaryotic chromosome. 5
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