10. Which one is a neutral substance? A) Salt water B) Milk C) Pure water D) Apple juice

6. What is the pH value of a neutral substance like water? A) 0 B) 7 C) 10 D) 14

5. Which everyday substance is an acid? A) Milk of magnesia B) Toothpaste C) Lemon juice D) Baking soda

3. Which of the following is a base? A) Vinegar B) Lemon juice C) Soap D) Orange juice

9. What type of substance is baking soda? A) Acid B) Base C) Neutral D) Salt

18. Which of the following is not commonly used to test acids and bases? A) Litmus paper B) pH paper C) Thermometer D) Universal indicator

11. What is a base? A) Tastes sour B) Turns blue litmus red C) Has a pH above 7 D) Makes gas bubbles in water

7. Which of these is NOT acidic? A) Lemon B) Vinegar C) Soap D) Cola

16. Which of these is the best way to test whether a substance is acidic or basic at home? A) Smell the substance B) Taste it carefully C) Use red cabbage juice as an indicator D) Heat it and observe

2. A solution turns universal indicator red. What does this tell us? A) It's neutral B) It's strongly acidic C) It's strongly basic D) It's weakly basic

12. Which of these substances is acidic? A) Ammonia B) Lemon juice C) Bleach D) Soap

1. What is the pH range of acids? A) 0–6 B) 7 C) 8–14 D) 5–10