Chemical Reactions and Equations Class 10: Extra Questions with Answers

In this comprehensive resource, you’ll find essential extra questions and answers related to CBSE Class 10 Science Chapter 1: Chemical Reactions and Equations. Whether you’re preparing for exams or simply want to reinforce your understanding, these practice questions cover crucial concepts.

Key Features:

1. Practice Questions: Dive into a curated set of additional questions that align with the CBSE syllabus. These questions span various difficulty levels, ensuring thorough preparation.
2. Answers and Solutions: Detailed solutions accompany each question, helping you grasp the underlying principles and mechanisms of chemical reactions.
3. NCERT Aligned: Our content adheres to the latest NCERT textbook, ensuring accuracy and relevance.

Extra Questions

1. What do you mean by chemical reactions. Give examples.Ans.  A reaction in which a new substance is formed from original substances is called a chemical reaction. For example: rusting of iron, digestion of food etc.
2. What are the four observations that are characteristic of a chemical reaction. List with examples.Ans  The four observations that are characteristics of a chemical reaction are:
   1. a) Change in state
   2. b) Change in colour
   3. c) Change in temperature
   4. d) Evolution of gas

   Burning Magnesium ribbon in air results in formation of magnesium oxide with dazzling white flame-this is an example where both change in state and change in temperature is seen.

   Reaction of aq solution of lead nitrate with potassium iodide involves change in state as well as change in colour as yellow-coloured precipitates of lead iodide are formed.

   Reaction of zinc granules with dil. HCl results in evolution of gas (Hydrogen) release of heat and also change in state.

3. Why do we need to balance a chemical equation?Ans    A chemical equation needs to be balanced in order to satisfy the law of conservation of mass that states that mass can neither be created nor destroyed in a chemical reaction.

    

4. What is an unbalanced chemical equation known asAns.    Skeletal equation
5. Name two salts that are used in black and white photography.Ans. Silver bromide (AgBr) and silver iodide (AgI) are commonly used in black and white photography.
6. What product is formed when quicklime (calcium oxide) reacts with water?Ans. Quicklime (CaO) reacts with water to form slaked lime (calcium hydroxide, Ca(OH)₂).
7. Write the chemical formula for marble.Ans. The chemical formula for marble is CaCO₃ (calcium carbonate).
8. Which type of reaction produces insoluble salts?Ans. Double displacement reactions often produce insoluble salts.
9. Why is the combustion of Liquified Petroleum Gas (LPG) considered a chemical change?Ans. LPG combustion results in the formation of a new substance that cannot revert to its original state.
10. What is the balanced equation for the reaction of potassium chlorate (KClO₃) on heating?Ans. 2KClO₃ (s) → 2KCl (s) + 3O₂ (g)
11. Why is hydrogen peroxide stored in colored bottles?Ans. Colored bottles protect hydrogen peroxide from light, preventing its decomposition.
12. Identify ‘x’, ‘y’, and ‘z’ in the following reaction:(a) x = gas; y = reaction condition; z = gas
    (b) x = solid; y = liquid; z = gas
    (c) x = number of moles of KClO₃; y = reaction condition; z = number of molecules of oxygen
    (d) x = physical state of KClO₃ and KCl; y = reaction condition; z = physical state of O₂
    Ans. The balanced chemical equation for the action of steam on iron is: [3Fe + 4H₂O → Fe₃O₄ + 4H₂]
13. Assertion (A): The balanced chemical equation for the action of steam on iron is: 3Fe + 4H₂O → Fe₃O₄ + 4H₂.
    Reason ®: The law of conservation of mass holds good for a chemical equation.Answer: Both (A) and ® are true, and reason ® is the correct explanation of the assertion (A)
14. State the law followed by balancing a chemical equation.Answer: The law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction. The total mass of elements in the products must be equal to the total mass of elements in the reactants in a balanced equation.
    Balanced Chemical Equation: 2Na (s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g)
15. Explain the significance of photosynthesis.Ans. Photosynthesis is the process by which plants utilize carbon dioxide and water in the presence of sunlight to produce glucose and oxygen. It sustains life for all living beings.
    Balanced Chemical Equation for Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
16. Write balanced chemical equations for the following reactions:(a) Hydrogen + Chlorine → Hydrogen chloride
          Ans. H₂ (g) + Cl₂ (g) → 2HCl (g)
    (b) Lead + Copper chloride → Lead chloride + Copper
          Ans. Pb (s) + CuCl₂ (aq) → PbCl₂ (aq) + Cu (s)
    (c) Zinc oxide + Carbon → Zinc + Carbon monoxide
          Ans. ZnO (s) + C (s) → Zn (s) + CO (g).
17. Classify the reaction: Calcium oxide reacts vigorously with water to produce slaked lime.Ans. This reaction is a combination reaction.

Class – 6

Maths

LCM and HCF Practice Questions

1. Find the HCF of 135 and 225 using the prime factorization method.

2. What is the HCF of 408 and 1032?

3. Find the LCM of 48, 96 and 108 by prime factorization method.

4. Is it possible to have two numbers whose HCF is 18 and LCM is 540?

5. Two milk tankers contain 450 litres and 600 litres of milk respectively. Find the maximum capacity of a container which can measure the milk of both the tankers when used an exact number of times.

6. Find the least number which when divided by 12, 15, 18 and 20 leaves a remainder 5 in each case.

7. Find the smallest 4-digit number which is divisible by 18, 24 and 32.

8. The length, breadth and height of a box are 75cm, 85cm and 95cm respectively. Find the longest tape which can measure the three dimensions of the box exactly.

9. In a morning walk, three girls step off together from the same spot. Their steps measure 66cm, 78cm and 90cm respectively. What is the minimum distance each should cover so that all can cover the distance in complete steps?

10. HCF of two numbers is 2 and product of two numbers is 2340. Find the LCM of two numbers.

Answer Key

1. 45
2. 24
3. 864
4. Yes
5. Maximum Capacity = 150 litres ; 3 ; 4
6. 185
7. 1152
8. 5 cm
9. 3960 cm
10. 1170

Class – IX                                            CSCE TUTORIAL                                               Science

Tissues

1. What do you mean by the term Tissue?

2. What are the three types of meristems?

3. Which meristem is present at growing tips of stem and roots?

4. Name the basic packing tissue of plant.

5. Name the tissue present in soft parts of the plants like pith and cortex.

6. Name the tissue found at the base of leaves.

7. What leads to increase in the girth of stem?

8. What feature helps aquatic plants to maintain buoyancy in Water?

9. Name the parenchyma which contains chlorophyll.

10. Name the tissue which is present in the veins of leaves.

11. Walls of sclerenchymatous cells are thickened. What causes the thickening?

12. Why epidermis of plants living in dry habitats is thicker?

13. What is the function of waxy covering on epidermis of aerial parts of plants?

14. Why are corks impervious to gases and water?

15. What is bast ? Enlist its major features and functions.

16. Write down the name of living cells of Xylem and Phloem.

17. Which complex permanent tissue conducts materials in both directions?

18. Which type of conducting tissues conduct water and minerals vertically?

19. Name the dead element of phloem.

20. What is the common name of:-
    a) Xylem                b) Phloem

21. Which type of tissue is found at shoot apex? Name another part of the plant body where this type of tissue is found.

22. Write a short note on different types of meristematic tissue with their location and function in plants.

23. Show the diagrammatic representation of location of lateral meristem and intercalary meristem in plant body.

24. What is the difference in aerenchyma and chlorenchyma.

25. Write the functions of following chemical substances found in plant tissues:
    (i) Lignin                                                              (ii) Cutin

26. Water hyacinth floats on water surface. Explain.

27. What are the functions of collenchyma in plants?

28. What is the role of epidermis in plants?

29. Answer the following :
    (i) How is the epidermis of the plants living in very dry habitats adapted?
    (ii)Write the functions of guard cells of stomata in the leaf.

30. Why is epidermis present as a thick waxy coating of cutin in desert plants?

31. Write a short note on vascular bundle.

32. Name the components of Xylem and draw a living component.

33. Draw a diagrammatic labeled sketch of stem tip to show location of merismatic tissue. Mention the function of different types of meristematic tissue.

34. Name the tissue responsible for the flexibility in plants. How would you differentiate it from other permanent tissue?

35. Describe three functions of protective tissue in plants.

36. Differentiate between Sclerenchyma and Parenchyma tissue. Draw well labeled diagram.

37. What are the characteristics of cork? How it is formed? Mention its role.

38. Write a note on the protective tissue in plants.

CSCE TUTORIAL

Class – IX                                                                                                                                                                              Science

Matter in Our Surroundings

1. Name the two gases which are supplied in compressed form in homes and hospitals.
2. Name the state of matter that have the tendency to maintain their shape when subjected to outside force.
3. Name any three substances that show sublimation.
4. What is dry ice?
5. Name the process which occurs when a drop of Dettol is added to water.
6. Name SI unit of measuring temperature. The boiling point of water is 100°C under normal atmospheric pressure. Convert this temperature to SI Units.
7. Give reasons for the following:
   (a) Gases fill up completely the vessel in which they are kept.
   (b) Gases exert pressure on the walls of the containing vessel.

8. Name three states of matter. Which state of matter is rigid and why?
9. List three characteristics of particles of matter. Describe one example for each characteristic to illustrate it. Name the characteristics which are responsible for
   a. spreading of smell of scent in a room and
   b. water taking the shape of the vessel in which poured.
10. To which physical state of matter, do the following statements apply?
    incompressible, no fixed shape
    incompressible, high melting point
    compressible, no definite volume
    incompressible, highly fluid.
11. Define (a) Compressibility (b) Rigidity (c) Fluidity
12. List any two properties of liquids which are common to gases.
13. State the physical state of water as the following temperatures.

(a) 373 K                             (b) 300 K                            (c) 200 K

14. A drop of ink and a drop of honey are placed in water in different beakers. Which of the two will spread faster? Give reason for your answer.
15. Explain why do wet clothes dry faster when we spread them out.
16. Name the state of matter in which:
    (i) Layers of particles can slip and slide over one another easily.
    (ii) Particles just move around randomly because of very weak force of attraction.

CSCE TUTORIAL

Coordinate Geometry

Class – X                                                                                                                                                                            Mathematics

1. Find a relation between x and y such that the point (x, y) is equidistant from the points (7, 1) and (3, 5).

2. Find a point on the y-axis equidistant from (-5, 2) and (9, -2)

3. Find the distance of the point (-3, 4) from the x-axis.

4. Find the distance of the point P (2, 3) from the x-axis.

5. Find the coordinates of the points of trisection (i.e., points dividing into three equal parts) of the line segment joining the points A(2, – 2) and B(– 7, 4).

6. Find the value of a when the distance between the points (3, a) and (4, 1) is √10.

7. Find the value of x, y if the distances of the point (x, y) from (- 3, 0) as well as from (3, 0) are 4.

8. If the points (2, 1) and (1, -2) are equidistant from the point (x, y), show that

x + 3y = 0.

9. Which point on the x-axis is equidistant from (5, 9) and (-4, 6)?

10. Find a point on the x-axis which is equidistant from the points (7, 6) and (-3, 4).

11. The length of a line segment is of 10 units, and the coordinates of one end-point are (2, -3). If the abscissa of the other end is 10, find the ordinate of the other end.

12. Show that the points A(- 4, -1), B(-2, – 4), C(4, 0) and D(2, 3) are the vertices points of a rectangle.

13. The points A (2, 9), B (a, 5) and C (5, 5) are the vertices of a triangle ABC, right-angled at B. Find the values of a and hence the area of triangle ABC.

14. Prove that the points (-2, 5), (0, 1) and (2, -3) are collinear.

15. The coordinates of point P are (-3, 2). Find the coordinates of the point Q, which lies on the line joining P and origin such that OP = OQ.

16. The three vertices of a parallelogram are (3, 4), (3, 8) and (9, 8). Find the fourth vertex.

17. Find a point which is equidistant from points A (-5, 4) and B (-1, 6). How many such points are there?

18. The centre of a circle is (2a, a – 7). Find the values of a if the circle passes through the point (11, -9) and has diameter 10√2 units.

19. Ayush starts walking from his house to the office. Instead of going to the office directly, he goes to the bank first, from there to his daughter’s school and then reaches the office. What is the extra distance travelled by Ayush in reaching the office? (Assume that all distances covered are in straight lines). If the house is situated at (2, 4), bank at (5, 8), school at (13, 14) and office at (13, 26) and coordinates are in kilometers.

20. Find the ratio in which the line segment joining the points (– 3, 10) and (6, – 8) is divided by (– 1, 6).

21. Find the coordinates of point A, where AB is the diameter of the circle whose centre is (2, -3) and B is (1, 4).

22. If (a, b) is the mid-point of the line segment joining the points A (10, -6), B(k, 4) and a – 2b = 18, find the value of k and the distance AB.

23. If P(9a – 2, -b) divides the line segment joining A(3a + 1, -3) and B(8a, 5) in the ratio 3 : 1, find the values of a and b.

24. If the points (-2, 1), (1, 0), (x, 3) and (1, y) form a parallelogram, find the values of x and y.