acid and base theories

Question 1

Bronsted-Lowry Theory

Answer 1

Acids are proton donors, bases are proton receivers

Question 2

Arrhenius

Answer 2

Acids ionise or dissociate in water to produce hydrogen ions, whilst bases dissociate to yield hydroxide ions.

Question 3

Bronsted-Lowry Advantages

Answer 3

• Explains the acidic or basic nature of some salts
• Can explain acid-base reactions in non-aqueous solution

Question 4

Bronsted-Lowry Disadvantages

Answer 4

• Does not explain acid-base reactions between acidic oxides such as SO₂ and basic oxides such as CaO
  CaO + SO₃ → CaSO₄
• Does not explain acid-base reactions in which protons are not transferred, e.g. the reaction between boron trifluoride and ammonia
  BF₃ + NH₃ → BF₃NH₃

Question 5

Arrhenius Advantages

Answer 5

identified that acids yield hydronium and bases produce hydroxide ions in solution

Question 6

Arrhenius Disadvantages

Answer 6

• did not explain why substances that do not contain hydroxide, such as NH3, were bases
• does not explain acidity and basicity of some salt solutions, doesn’t explain reactions that are not occurring in solution