Class 10 Chemical Reactions and Equations Previous Years Questions

Previous Years Questions Notes Important Questions

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Previous Years Questions : Solutions

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Chemical Reactions and Equations Previous Years Questions

1. Select the appropriate state symbols of the products given as X and Y in the following chemical equation by choosing the correct option from table given below:
   Zn(s) + H₂SO₄(l) → ZnSO₄(X) + H₂(Y)
   a. X is (s) and Y is (l)
   b. X is (aq) and Y is (g)
   c. X is (aq) and Y is (s)
   d. X is (g) and Y is (aq) [1 mark] [CBSE 2023]
2. Consider the following chemical equation I and II
   I. Mg + 2HCl → MgCl₂ + H₂
   II. NaOH + HCl → NaCl + H₂O
   The correct statement about these equations is :
   a. ‘I’ is a displacement reaction and ‘II’ is a decomposition reaction.
   b. ‘I’ is a displacement reaction and ‘II’ is double displacement reaction.
   c. Both ‘I’ and ‘II’ are dispalcement reactions.
   d. Both ‘I’ and ‘II’ are double displacement. [1 mark] [ CBSE 2023]
3. To balance the following chemical equation to the values of x and y should respectively be :
   2NaOH + xAl₂O₃ → yNaAlO₂ + H₂O
   a. 1, 4
   b. 1, 2
   c. 2, 4
   d. 2, 3 [1 mark] [ CBSE 2023]
4. Strong heating of ferrous sulphate leads to the formation of a brown solid and two gases. This reaction can be categorised as:-
   a. displacement and redox
   b. decomposition and redox
   c. displacement and endothermic
   d. decomposition and exothermic [1 mark] [CBSE 2020]
5. State whether the given chemical reaction is a redox reaction or not. Justify your answer.
   MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂ [2 mark] [CBSE 2023]
6. A Metal nitratee ‘A’ on heating gives a metal oxide along with the evolution of a brown coloured gas ‘B’ and a colourless gas, which helps in burning. Aqueous solution of ‘A’ when reacted with pottasium iodide forms a yellow preciopitate.
   1. Identify ‘A’ and ‘B’
   2. Name the types of both the reactions involved in the above statement. [2 marks] [CBSE 2023]
7. What is observed after about 1 hour of adding the strips of copper and aluminium separately to ferrous sulphate solution filled in two beakers? Name the reaction if any change in colour is noticed. Also,write chemical equation for the reaction. [2 marks] [CBSE 2019]
8. A student wants to study a decomposition reaction by taking ferrous sulphate crystals. Write two precautions he must observe while performing the experiment. [2 marks] [CBSE 2019]
9. What is observed when a solution of sodium sulphate is added to a solution of barium chloride taken in a test tube ? Write equation for the chemical reaction involved & name the type of reaction in this case. [2 marks] [CBSE 2018]
10. State the change in colour observed in each of the following cases mentioning the reason :
    (i) Silver chloride is exposed to sunlight.
    (ii) A piece of zinc is dipped in ferrous sulphate solution.
    (iii) Copper powder is strongly heated in air. [3 mark] [CBSE 2023]
11. With the help of an appropriate example, justify that some of the chemical reactions are determined by
    1. Change in temperature,
    2. Evolution of gas, and
    3. Change in colour [3 mark] [CBSE 2023]
12. A shining metal ‘M’ on burning gives a dazzling white flame & changes to a white powder ‘N’.
    1. Identify ‘M’ & ‘N’.
    2. Represent the above reaction in the form of a balanced chemical equation .
    3. Does ‘M’ undergo oxidation or reduction in this reaction ? Justify. [3 marks] [CBSE 2020]
13. In the electrolysis of water,
    1. Name the gases liberated at anode & cathode.
    2. Why is it that the volume of gas collected on one electrode is two times that on the other electrode?
    3. What would happen if dilute H₂SO₄ is not added to water? [3 marks] [CBSE 2020]
14. .
    1. What is a double displacement reaction? Explain with an example.
    2. A small amount of quick lime is added to water in a beaker.
       1. Name and define the type of reaction that has taken place.
       2. Write balanced chemical equation for the above reaction and the chemical name of the product formed.
       3. List two main observations of this reaction. [3 marks] [CBSE 2019]
15. .
    1. Design an activity to demonstrate the decomposition reaction of lead nitrate.
    2. Draw labelled diagram of the experimental setup. List two main observations.
    3. Write balanced chemical equation for the reaction stating the physical state of the reactant & the products. [5 marks] [CBSE 2019]
16. Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants. Write one equation each for decomposition reaction where energy is supplied in the form of heat, light and electricity. [3 marks] [CBSE 2018]

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Previous Years Questions : Solutions

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