arrow_backBack to Study Resources

Quiz Chapter 6: Acid and Alkali

10 questions · Form 2 Science Bab 6: Acid and Alkali

Question 1 of 10Score: 0

Which of the following household items contains an acid?

Full Question List & Answer Key

Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.

1. Which of the following household items contains an acid?

  1. Detergent powder
  2. Vinegar
  3. Soap bar
  4. Toothpaste
Show answer

Answer: B

Vinegar contains ethanoic (acetic) acid, giving it a sour taste and low pH.

2. Which action should be taken before discharging acidic effluent from factories into nearby rivers?

  1. Cooling the effluent without treatment
  2. Adding an alkali such as lime to neutralise the acid
  3. Adding more concentrated acid to dilute it
  4. Boiling the effluent to evaporate the acid
Show answer

Answer: B

Treating acidic industrial waste with an alkali neutralises the acid, preventing aquatic pollution and harm to river ecosystems.

3. Which pH value indicates a strong acid solution?

  1. pH 1
  2. pH 5
  3. pH 7
  4. pH 13
Show answer

Answer: A

The pH scale ranges from 0 to 14. A pH value closest to 0 (such as pH 1) represents a strong acid.

4. Why is toothpaste formulated to be mildly alkaline?

  1. To increase the production of bacteria in the mouth
  2. To neutralise organic acids produced by oral bacteria from food debris
  3. To react with enamel to generate hydrogen gas
  4. To lower the pH of saliva below 4
Show answer

Answer: B

Oral bacteria break down food remnants into acids that decay tooth enamel; mildly alkaline toothpaste neutralises these acids.

5. Why do farmers add slaked lime (calcium hydroxide) to agricultural soil?

  1. To increase soil acidity for better seed germination
  2. To neutralise overly acidic soil and improve crop growth
  3. To kill earthworms and insects
  4. To increase soil moisture retention
Show answer

Answer: B

Slaked lime is an alkaline substance added to acidic soil to neutralise excess acidity and achieve an optimal pH for crops.

6. What happens when a piece of dry blue litmus paper is placed into dry citric acid crystals?

  1. It turns red immediately
  2. It turns white due to bleaching
  3. No color change occurs
  4. It turns green
Show answer

Answer: C

Acids require water to ionize and produce hydrogen ions; without water, dry acid crystals cannot exhibit acidic properties to turn dry blue litmus paper red.

7. What products are formed during a complete neutralisation reaction between an acid and an alkali?

  1. Salt and Hydrogen gas
  2. Salt and Carbon dioxide
  3. Salt and Water
  4. Alkali and Oxygen gas
Show answer

Answer: C

Neutralisation is the reaction between an acid and a base/alkali that produces salt and water only.

8. What salt is produced when Nitric Acid neutralises Potassium Hydroxide?

  1. Potassium Chloride
  2. Potassium Nitrate
  3. Calcium Nitrate
  4. Potassium Sulphate
Show answer

Answer: B

Nitric Acid + Potassium Hydroxide → Potassium Nitrate + Water.

9. What salt is formed when Hydrochloric Acid reacts with Calcium Hydroxide?

  1. Calcium Chloride
  2. Calcium Sulphate
  3. Sodium Chloride
  4. Calcium Carbonate
Show answer

Answer: A

Hydrochloric Acid + Calcium Hydroxide → Calcium Chloride + Water.

10. Which indicator turns RED in an acidic solution and YELLOW in an alkaline solution?

  1. Phenolphthalein
  2. Methyl Orange
  3. Litmus Paper
  4. Filter Paper
Show answer

Answer: B

Methyl Orange turns red in acidic conditions and yellow in neutral or alkaline conditions.

Sponsored