Acids, Bases and Salts

Notes

A. Objective Questions (MCQs)

1. Which ion is produced by acids in aqueous solution?

A. OH⁻ B. H⁺ C. Na⁺ D. Cl⁻

Answer: B. H⁺

2. Which of the following is a natural indicator?

A. Phenolphthalein B. Methyl Orange C. Litmus D. Universal Indicator

Answer: C. Litmus

3. Which gas is evolved when zinc reacts with hydrochloric acid?

A. Oxygen B. Carbon dioxide C. Hydrogen D. Nitrogen

Answer: C. Hydrogen

4. The pH of a neutral solution is

A. 0 B. 5 C. 7 D. 14

Answer: C. 7

5. Which acid is present in vinegar?

A. Citric acid B. Acetic acid C. Hydrochloric acid D. Nitric acid

Answer: B. Acetic acid

6. Which base is used in whitewashing?

A. NaOH B. KOH C. Ca(OH)₂ D. Mg(OH)₂

Answer: C. Calcium Hydroxide

7. Which salt is commonly known as baking soda?

A. Na₂CO₃ B. NaHCO₃ C. CaCO₃ D. NH₄Cl

Answer: B. NaHCO₃

8. Which substance is used in toothpaste to reduce acidity?

A. Acid B. Base C. Salt D. Water

Answer: B. Base

9. Which indicator becomes pink in a basic solution?

A. Litmus B. Turmeric C. Phenolphthalein D. Methyl Orange

Answer: C. Phenolphthalein

10. Neutralization reaction produces

A. Acid and Water

B. Salt and Water

C. Base and Water

D. Salt and Acid

Answer: B. Salt and Water

B. Very Short Answer Questions (1 Mark) Q1. What is an acid?

Answer: An acid is a substance that produces H⁺ ions in aqueous solution.

Q2. What is a base?

Answer: A base is a substance that produces OH⁻ ions in aqueous solution.

Q3. Name one natural indicator.

Answer: Litmus.

Q4. What is the pH of pure water?

Answer: 7.

Q5. Which gas is evolved when an acid reacts with a metal?

Answer: Hydrogen gas.

Q6. Name one alkali.

Answer: Sodium hydroxide (NaOH).

Q7. What is neutralization?

Answer: The reaction between an acid and a base to form salt and water is called neutralization.

Q8. Which acid is found in lemon?

Answer: Citric acid.

Q9. Name the acid present in our stomach.