Shortcomings of the Arrhenius Theory

Question 1

List the 3 shortcomings of the Arrhenius theory

Answer 1

1. It is hydronium ions, not bare H+ ions suggested by Arrhenius, that exist in solution.
2. He restricted his definitions to aqueous solutions.
   Solvents such as liquid ammonia, benzene and methylbenzene are excluded from his definitions.
3. Not all acid-base reactions require water.
   e.g. when ammonia gas and hydrogen chloride gas come in contact, white fumes of ammonium chloride are formed.
   The Arrhenius definition disallows us to clarify this as an acid-base reaction as no water is present.