11. According to Arrhenius, an acid is a substance that:

• A) Donates a proton
• B) Donates a hydroxide ion
• C) Produces hydrogen ions (H⁺) in water
• D) Accepts an electron
• Answer: C

12. A base according to the Arrhenius definition is a substance that:

• A) Donates a proton
• B) Produces hydroxide ions (OH⁻) in water
• C) Accepts a hydroxide ion
• D) Accepts a proton
• Answer: B

13. Which of the following is a strong acid?

• A) Acetic acid
• B) Hydrochloric acid
• C) Ammonia
• D) Sodium hydroxide
• Answer: B

14. The Bronsted-Lowry theory defines an acid as a:

• A) Proton donor
• B) Electron donor
• C) Proton acceptor
• D) Electron acceptor
• Answer: A

15. Which of the following is NOT a property of acids?

• A) Sour taste
• B) Turns blue litmus red
• C) Produces OH⁻ ions in solution
• D) Conducts electricity in aqueous solutions
• Answer: C

16. A solution has a pH of 3. This means it is:

• A) Neutral
• B) Strongly basic
• C) Weakly acidic
• D) Strongly acidic
• Answer: D

17. What is the pH of a neutral solution at 25°C?

• A) 0
• B) 7
• C) 14
• D) 1
• Answer: B

18. A substance that increases the concentration of OH⁻ ions in aqueous solution is a(n):

• A) Acid
• B) Base
• C) Neutral substance
• D) Salt
• Answer: B

19. Which of the following is a weak base?

• A) NaOH
• B) NH₃
• C) KOH
• D) HCl
• Answer: B

20. What is the conjugate base of ( H_2O )?

• A) OH⁻
• B) H₃O⁺
• C) ( O_2^- )
• D) ( H_2 )
• Answer: A