Acid, Base and Salt

1. What gas is produced when an acid like hydrochloric acid reacts with a metal like zinc?

• A) Oxygen
• B) Carbon dioxide
• C) Nitrogen
• D) Hydrogen

2. What are materials like litmus paper, which change color to identify acids or bases, called?

• A) Catalysts
• B) Solvents
• C) Indicators
• D) Reactants

3. Based on the chemical definition provided, why is Methane (CH₄) not considered an acid despite containing hydrogen atoms?

• A) It is a gas at room temperature.
• B) It does not produce H+ ions in water.
• C) It contains carbon atoms.
• D) It does not taste sour.

4. According to the text, the industrial progress of a country can be judged by the quantity of which acid it uses?

• A) Hydrochloric acid (HCl)
• B) Nitric acid (HNO3)
• C) Sulphuric acid (H₂SO₄)
• D) Acetic acid (CH3COOH)

5. What color change occurs when blue litmus paper is dipped in an acidic solution?

• A) It turns red
• B) It turns green
• C) It remains blue
• D) It becomes colorless

6. What two substances are produced when dilute hydrochloric acid is added to limestone (CaCO₃)?

• A) Calcium oxide and water
• B) Calcium hydride and chlorine gas
• C) Calcium chloride and hydrogen gas
• D) Calcium chloride and carbon dioxide gas

7. What are the main products when an acid and a base, such as sulphuric acid and calcium hydroxide, react?

• A) A new acid and a new base
• B) Salt and hydrogen gas
• C) Salt and water
• D) Metal oxide and carbon dioxide