Ayush Singh

Comeback era

PRACTICE PAPER 1
Class 10 - Science
Time Allowed: 2 hours Maximum Marks: 60
1. You have been provided with three test tubes. One of them contains distilled [2]
water and the other two contain an acidic solution and a basic solution
respectively. If you are given only red litmus paper, how will you identify the
contents of each test tube?

2. Why should curd and sour substances not be kept in brass and copper vessels? [1]

3. Which gas is usually liberated when an acid reacts with a metal? Illustrate with an [2]
example. How will you test for the presence of this gas?

4. Metal compound A reacts with dilute hydrochloric acid to produce effervescence. [2]
The gas evolved extinguishes a burning candle. Write a balanced chemical
equation for the reaction if one of the compounds formed is calcium chloride.

5. Why do HCl, HNO3 etc. show acidic characters in aqueous solution while solutions [1]
of compounds like alcohol and glucose do not show acidic character?

6. Why does an aqueous solution of an acid conduct electricity? [1]

7. Why does dry HCl gas not change the colour of the dry litmus paper? [1]

8. You have two solutions. A and B, the pH of solution A is 6 and pH of solution B is [2]
8. Which solution has more hydrogen ion concentration? Which of this is acidic
and which one is basic?

9. What will happen if a solution of sodium hydrocarbonate is heated? Give the [1]
equation of the reaction involved.

10. Write an equation to show the reaction between Plaster of Paris and water. [2]

11. Name the sodium compound which is used for softening hard water. [1]

12. Why is diffusion insufficient to meet the oxygen requirements of multicellular [2]
organisms like humans?

13. What criteria do we use to decide whether something is alive? [2]

14. What are the differences between autotrophic nutrition and heterotrophic [2]
nutrition?
15. Where do the plants get each of raw materials required for photosynthesis? [2]

16. What is the role of the acid in our stomach? [1]

17. What is the function of digestive enzymes? [2]

18. How are the lungs designed in human beings to maximize the area for exchange [2]
of gases?

19. Which of the statements about the reaction below are incorrect? [1]
2PbO(s) + C(s) → 2Pb(s) + CO2(g)
a. Lead is getting reduced.
b. Carbon dioxide is getting oxidised.
c. Carbon is getting oxidized.
d. Lead oxide is getting reduced.

a) (a), (b) and (c) b) (a) and (c)

c) (a) and (b) d) All of these

20. What is a balanced chemical equation? Why should chemical equations be [2]
balanced?

21. Translate the following statement into a chemical equation and then balance it: [1]
Hydrogen sulphide gas burns in air to give water and sulphur dioxide.

22. Write the balanced chemical equation for the following reaction and identify the [1]
type of reaction.
Magnesium (s) + Hydrochloric acid (aq) → ​Magnesium chloride (aq) + Hydrogen
(g)

23. Write the balanced chemical equation for the following reaction and identify the [2]
type of reaction.
Hydrogen (g) + Chlorine (g) → Hydrogen chloride (g)

24. Define the principal focus of a concave mirror. [1]

25. Light enters from air to glass having refractive index 1.50. What is the speed of [2]
8 -1
light in the glass? The speed of light in vacuum is 3 × 10 ms .

26. A ray of light travelling in air enters obliquely into water. Does the light ray bend [2]
towards the normal or away from the normal? Why?

27. A convex lens forms a real and inverted image of a needle at a distance of 50 cm [2]
from it. Where is the needle placed in front of the convex lens if the image is
equal to the size of the object? Also, find the power of the lens.
28. Define 1 dioptre of power of a lens. [2]

29. Why do we prefer a convex mirror as a rear view mirror in vehicles? [2]

30. Find the focal length of a convex mirror whose radius of curvature is 32 cm. [2]

31. A concave mirror produces three times magnified (enlarged) real image of an [2]
object placed at 10 cm in front of it. Where is the image located?

32. The radius of curvature of a spherical mirror is 20 cm. What is its focal length? [1]

33. Name a mirror that can give an erect and enlarged image of an object. [1]

34. What is meant by power of accommodation of eye? [2]

35. A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What [2]
should be the type of the corrective lens used to restore proper vision?

36. What is the far point and near point of the human eye with normal vision? [1]

37. A student has difficulty reading the blackboard while sitting in the last row. What [2]
could be the defect the child is suffering from? How can it be corrected?