Latest Updated CBSE Class 10 Science CH-02 Acids Bases and Salts

CBSE Class 10 Science Notes CH-2 Acids Bases and Salts

 Here’s a concise summary of CBSE Class 10 Science Chapter 2: Acids, Bases, and Salts:

1. Key Concepts

  • Acids: Sour taste, turn blue litmus red, release H⁺ ions in water.
  • Bases: Bitter taste, soapy touch, turn red litmus blue, release OH⁻ ions in water.
  • Salts: Neutral compounds formed by acid-base neutralization.

2. Important Reactions

  • Acid + Base → Salt + Water (Neutralization)
  • Acid + Metal → Salt + Hydrogen gas
  • Base + Non-metal Oxide → Salt + Water

3. pH Scale

  • Measures acidity/basicity (0-14 scale).
  • pH < 7: Acidic; pH = 7: Neutral; pH > 7: Basic.

4. Key Processes

  • Water of Crystallization: Bound water in salts (e.g., gypsum → plaster of Paris).
  • Common Compounds:
    • Baking soda (NaHCO₃): Used in cooking and cleaning.
    • Washing soda (Na₂CO₃·10H₂O): Used in detergents.
    • Bleaching powder (Ca(OCl)₂): Disinfectant.

This chapter focuses on practical applications and key chemical principles.

Most Important Science Class 10 Questions Answers 

1. What happens when acids react with metals? Write a chemical equation.

  • Answer: Acids react with metals to form salt and hydrogen gas.
    Example:
    2HCl+ZnZnCl2+H22HCl + Zn \rightarrow ZnCl_2 + H_2

2. What is the pH value of a neutral solution? Explain its importance.

  • Answer: The pH of a neutral solution is 7. It indicates equal concentrations of H⁺ and OH⁻ ions, essential for biological and chemical balance.

3. Write the chemical name and formula of:

  • Baking soda: Sodium bicarbonate, NaHCO₃
  • Washing soda: Sodium carbonate decahydrate, Na₂CO₃·10H₂O

4. How is the plaster of Paris prepared? Write its uses.

  • Answer:
    • Preparation: Heating gypsum at 373K:
      CaSO42H2O373KCaSO412H2O+1.5H2OCaSO₄·2H₂O \xrightarrow{373K} CaSO₄·\frac{1}{2}H₂O + 1.5H₂O
    • Uses: Making molds, casts, and as a building material.

Also Read:- Latest Updated CBSE Class 10 Science CH-01 Chemical Reactions and Equations


Most Important MCQs Science Class 10 

1. What is the pH of a neutral solution?

a) 0
b) 7
c) 14
d) 10
Answer: b) 7

2. Which of the following is a strong acid?

a) HCl
b) CH₃COOH
c) H₂CO₃
d) NaOH
Answer: a) HCl

3. What is the chemical formula of sodium bicarbonate?

a) Na₂CO₃
b) NaHCO₃
c) NaOH
d) NaCl
Answer: b) NaHCO₃

4. Which gas is produced when an acid reacts with a metal?

a) Oxygen
b) Carbon dioxide
c) Hydrogen
d) Nitrogen
Answer: c) Hydrogen

5. What is the formula for sodium carbonate?

a) Na₂CO₃·10H₂O
b) Na₂SO₄
c) NaCl
d) Na₂CO₃
Answer: d) Na₂CO₃

6. Which of the following is formed when an acid reacts with a base?

a) Water and salt
b) Water and gas
c) Salt and metal
d) Salt and oxygen
Answer: a) Water and salt

7. Which one of the following is used in making glass?

a) Sodium chloride
b) Sodium hydroxide
c) Sodium bicarbonate
d) Sodium carbonate
Answer: d) Sodium carbonate

These MCQs cover the key concepts from the chapter and will be useful for practice!

Board Exam Class 10 Science Revision Notes


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