Class 10 Science · Chapter 2

Acids, Bases and Salts

352 Class 10 Science questions on Acids, Bases and Salts from the NCERT textbook, NCERT Exemplar and CBSE board papers 2018–2026, each with its answer and a step-by-step solution.

CBSE Class 10 Science previous year papers, with answers →

Questions · page 8 of 18

1. Q141 CBSE 2025
   The warning ​sign ​shown ​in the given figure must invariably be displayed/pasted ​on ​the containers which ​contain hydroxide of ​:

   1. (a)Aluminium
   2. (b)Calcium
   3. (c)Sodium
   4. (d)Magnesium
   Show answer

   (c) Sodium

   Step-by-step solution →
2. Q142 CBSE 2025
   Which ​of ​the given ​option represents a ​family ​of salts ​?

   1. (a)$\text{NaCl},{\text{Na}}_2{\text{SO}}_4,{\text{CaSO}}_4$
   2. (b)${\text{K}}_2{\text{SO}}_4,{\text{Na}}_2{\text{SO}}_4,{\text{CaSO}}_4$
   3. (c)${\text{NaNO}}_3,{\text{CaCO}}_3,{\text{Na}}_2{\text{CO}}_3$
   4. (d)${\text{MgSO}}_4,{\text{CuSO}}_4,{\text{MgCl}}_2$
   Show answer

   (b) ${\text{K}}_2{\text{SO}}_4,{\text{Na}}_2{\text{SO}}_4,{\text{CaSO}}_4$

   Step-by-step solution →
3. Q143 CBSE 2025
   In order to prepare ​dry hydrogen ​chloride gas ​in humid atmosphere the ​gas produced is passed through a ​guard ​tube (drying tube) which contains :

   1. (a)Calcium chloride
   2. (b)Calcium oxide
   3. (c)Calcium hydroxide
   4. (d)Calcium carbonate
   Show answer

   (a) Calcium chloride

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4. Q144 CBSE 2025
   You have three ​aqueous solutions A, ​B and C as given below : A - ​Potassium nitrate B - Ammonium chloride C ​- Sodium carbonate The ascending order ​of ​the pH of these ​solutions ​is :

   1. (a)$A<B<C$
   2. (b)$B<C<A$
   3. (c)$C<A<B$
   4. (d)$B<A<C$
   Show answer

   (d) $B<A<C$

   Step-by-step solution →
5. Q145 CBSE 2025
   The formula of washing soda is

   1. (a)${\text{NaHCO}}_3\cdot 6{\text{H}}_2\text{O}$
   2. (b)${\text{Na}}_2{\text{CO}}_3\cdot 6{\text{H}}_2\text{O}$
   3. (c)${\text{NaHCO}}_3\cdot 10{\text{H}}_2\text{O}$
   4. (d)${\text{Na}}_2{\text{CO}}_3\cdot 10{\text{H}}_2\text{O}$
   Show answer

   (d) ${\text{Na}}_2{\text{CO}}_3\cdot 10{\text{H}}_2\text{O}$

   Step-by-step solution →
6. Q146 CBSE 2025
   The following table shows the ​pH values of ​four solutions ​A, B, C ​and D ​on a pH scale : The solutions A, B, ​C and ​D ​respectively are of a

   1. (a)Strong acid, weak acid, neutral, strong base
   2. (b)Weak acid, neutral, weak base, strong base
   3. (c)Weak acid, neutral, strong base, weak base
   4. (d)Weak acid, neutral, strong base, strong acid
   Show answer

   (d) Weak acid, neutral, strong base, strong acid

   Step-by-step solution →
7. Q147 CBSE 2025
   The body of human beings ​works within the ​pH range ​of ​:

   1. (a)$6.1$ to $6.8$
   2. (b)$6.5$ to $7.3$
   3. (c)$7.0$ to $7.8$
   4. (d)$7.5$ to $8.1$
   Show answer

   (c) $7.0$ to $7.8$

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8. Q148 CBSE 2025
   Juice of ​tamarind ​turns blue ​litmus to red. ​It is because of ​the presence of an acid called :

   1. (a)Oxalic acid
   2. (b)Lactic acid
   3. (c)Methanoic acid
   4. (d)Tartaric acid
   Show answer

   (d) Tartaric acid

   Step-by-step solution →
9. Q149 CBSE 2025
   A common feature observed ​in ​the crystals of ​washing soda, copper ​sulphate, gypsum ​and ferrous ​sulphate ​is that all

   1. (a)exhibit basic nature
   2. (b)exhibit acidic nature
   3. (c)have fixed number of molecules of water of crystallisation in one formula unit of these salts.
   4. (d)are coloured
   Show answer

   (c) have fixed number of molecules of water of crystallisation in one formula unit of these salts.

   Step-by-step solution →
10. Q150 CBSE 2025
    In one formula ​unit ​of salt ‘X’, seven ​molecules of ​water of crystallisation ​are present. The salt ​‘X’ is :

    1. (a)${\text{CuSO}}_4$
    2. (b)${\text{Na}}_2{\text{CO}}_3$
    3. (c)${\text{FeSO}}_4$
    4. (d)${\text{CaSO}}_4$
    Show answer

    (c) ${\text{FeSO}}_4$

    Step-by-step solution →
11. Q151 CBSE 2025
    A ​few pieces of granulated zinc are taken in ​a test tube ​and $2$ mL of ​sodium hydroxide solution is ​added to ​it. When the contents are warmed, ​the ​product formed is :

    1. (a)${\text{Na}}_2\text{ZnO}$
    2. (b)${\text{NaZnO}}_2$
    3. (c)${\text{Na}}_2{\text{ZnO}}_2$
    4. (d)${\text{NaZn(OH)}}_2$
    Show answer

    (c) ${\text{Na}}_2{\text{ZnO}}_2$

    Step-by-step solution →
12. Q152 CBSE 2025
    The chlorine ​produced during the electrolysis ​of ​brine solution is used ​in the manufacture ​of :

    1. (a)Ammonia
    2. (b)Disinfectants
    3. (c)Plaster of Paris
    4. (d)Soaps and detergents
    Show answer

    (b) Disinfectants

    Step-by-step solution →
13. Q153 CBSE 2025
    Consider the ​following reactions :

    1. (i)Dilute hydrochloric ​acid reacts with ​sodium hydroxide.
    2. (ii)​Magnesium oxide reacts with dilute hydrochloric acid.
    3. (iii)Carbon dioxide ​reacts with sodium hydroxide. It is found that ​in ​each case ​:

    1. (a)Salt and water is formed.
    2. (b)Neutral salts are formed.
    3. (c)Hydrogen gas is formed.
    4. (d)Acidic salts are formed.
    Show answer

    (a) Salt and water is formed.

    Step-by-step solution →
14. Q154 CBSE 2025
    Tooth enamel ​is made up ​of ​calcium ​hydroxyapatite ​(a crystalline form of calcium phosphate). This chemical starts ​corroding in the mouth when ​the pH is :

    1. (a)$7$
    2. (b)$5$
    3. (c)$10$
    4. (d)$14$
    Show answer

    (b) $5$

    Step-by-step solution →
15. Q155 CBSE 2025
    When a mixture of ​baking ​soda and tartaric acid is heated (or mixed in ​water) a product ‘X’ is formed, ​which is ​responsible for making breads and cakes soft and spongy. The product ‘X’ ​is

    1. (a)Carbon dioxide
    2. (b)Carbon monoxide
    3. (c)Sodium tartrate
    4. (d)Hydrogen
    Show answer

    (a) Carbon dioxide

    Step-by-step solution →
16. Q156 CBSE 2025
    Juice of ​tamarind ​turns ​blue litmus to ​red. It ​is because ​of ​the presence of a chemical ​compound called

    1. (a)Acetic acid
    2. (b)Methanoic acid
    3. (c)Oxalic acid
    4. (d)Tartaric acid
    Show answer

    (d) Tartaric acid

    Step-by-step solution →
17. Q157 CBSE 2025
    The ​nature ​of ​aqueous solution of potassium ​nitrate ​is ​:

    1. (a)acidic
    2. (b)basic
    3. (c)neutral
    4. (d)alkaline
    Show answer

    (c) neutral

    Step-by-step solution →
18. Q158 CBSE 2025
    One ​formula unit ​of ​which one of the following ​salts has seven ​molecules ​of water ​of crystallisation ?

    1. (a)${\text{CaSO}}_4$
    2. (b)${\text{CuSO}}_4$
    3. (c)${\text{FeSO}}_4$
    4. (d)${\text{Na}}_2{\text{CO}}_3$
    Show answer

    (c) ${\text{FeSO}}_4$

    Step-by-step solution →
19. Q159 CBSE 2025
    The water of crystallization ​is present ​in

    1. (i)​Bleaching Powder
    2. (ii)​Plaster of Paris
    3. (iii)​Washing ​Soda
    4. (iv)Baking Soda

    1. (a)(ii) and (iv)
    2. (b)(ii) and (iii)
    3. (c)(i) and (iii)
    4. (d)(i) and (iv)
    Show answer

    (b) (ii) and (iii)

    Step-by-step solution →
20. Q160 CBSE 2025
    Two ​statements are given — ​one labelled as Assertion (A) ​and ​the ​other labelled as Reason (R). ​Select ​the correct answer to this question from the codes (a), (b), (c) and ​(d) as given below.

    Assertion (A): Sodium sulphate is a neutral salt.

    Reason (R): Sodium sulphate is a salt formed by a strong acid and a strong base.

    1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    2. (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
    3. (c)Assertion (A) is true, but Reason (R) is false.
    4. (d)Assertion (A) is false, but Reason (R) is true.
    Show answer

    (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

    Step-by-step solution →