Class 10 Acids, Bases and Salts Previous Years Questions

Previous Years Questions Notes Important Questions

Acids, Bases and Salts Previous Years Questions

1. Few drops of aqueous solution of ammonium chloride are put on a universal indicator paper. The paper turns pink.
   Study the following table and choose the correct option. [1 mark] [ CBSE 2023]
   
2. Two salts ‘X’ and ‘Y’ are dissolved in water separately. when phenolphthalein is added to these two solutions, the solutions ‘X’ turns pink and the solution ‘Y’ does not show any change in colour, therefore ‘X’ and ‘Y’ are
   a. X is Na₂CO₃ and Y is NH₄Cl
   b. X is Na₂SO₄ and Y is NaHCO₃
   c. X is NH₄Cl and Y is Na₂SO₄
   d. X is NaNO₃ and Y is Na₂SO₄ [1 mark] [CBSE 2023]
3. There are four solutions A, B, C and D with pH values as follows :-
   
   
   Which solutions would liberate hydrogen gas with zinc ?
   a. A only
   b. D only
   c. A and D only
   d. B and c only [1 mark] [CBSE2023]
4. Assertion (A) : It is advised that while diluting an acid one should add water to acid and not acid to water keeping the solution continuously stirred.
   Reason (R) : The process of dissolving an acid into water is highly exothermic.
   Answer the question selecting appropriate options given below :
   a. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of (A).
   b. Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of (A).
   c. Assertion (A) is true, but Reason (R) is false.
   d. Assertion (A) is false, but Reason (R) is true. [1 mark] [CBSE 2023]
5. A solution turns the colour of turmeric to reddish brown. if the same solution is poured on universal indicator, its colour would change to :
   a. violet
   b. blue
   c. red
   d. green [1 mark] [CBSE 2023]
6. If 10 ml of H₂SO₄ is mixed with 10 ml of Mg(OH)₂ of the same concentration, the resultant solution will give the following colour with universal indicator:
   a. Red
   b. yellow
   c. Green
   d. Blue [1 Mark] [CBSE 2020]
7. . A substance ‘X’ is used as a building material and is insoluble in water. when it reacts with dil. HCl, it produces a gas which turns lime water milky.
   1. Write the chemical name and formula of ‘X’.
   2. Write chemical equations for the chemical reactions involved in the above statements. [3 marks] [CBSE 2023]
8. A metal ‘M’ on reacting with dilute acid liberates a gas ‘G’. The same metal also liberates gas ‘G’ when reacts with a base.
   1. Write the name of gas ‘G’.
   2. How will you test the presence of this gas?
   3. Write chemical equations for the reactions of the metal with (i) an acid and (ii) a base. [3 marks] [CBSE 2023]
9. 1. what property do acids and bases have in common ? Explain it with an example.
   2. A compound which is prepared from gypsum has the property of hardening when mixed with water.
      Identify the compound and write its formula. How is this compound prepared ? Describe it in the form of a chemical equation only. [3 marks] [CBSE 2023]
10. 1. Write the chemical name and molecular formula of tooth enamel.
    2. How does it get corroded ? What is the preventive measure for this ? [3 marks] [CBSE 2023]
11. A chemical compound ‘X’ is used in the soap and glass industry. It is prepared from brine.
    1. Write the chemical name, common name and chemical formula of ‘X’.
    2. Write the equation involved in its preparation.
    3. What happens when it is treated with water containing Ca or Mg salts? [3 Marks] [CBSE 2020]
12. Write the chemical formula of washing soda. How can it be obtained from baking soda ? List two industries in which washing soda is used for other purposes than washing clothes. [3 Marks] [CBSE 2019]
13. State the effect of concentration of H⁺ (aq) ions on the nature of the solution. Do basic solutions also have H⁺ (aq) ions ? If yes, then why are these basic? [3 Marks] [CBSE 2019]
14. 2 mL of sodium hydroxide is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid. [3 Marks] [CBSE 2018]
15. The pH of salt used to make tasty and crispy pakoras is 14. Identify the salt and write a chemical equation for its formation. List its two uses. [3 Marks] [CBSE 2018]