Answer:
The correct answer is b. a substance that is a hydrogen ion donor
Explanation:
According to Arrhenius Theory, a base is all that substance that when dissolved releases hydroxyl ions (OH–). The bases are also known as alkalis, because when the hydroxyl groups dissociate and release, the pH of the solutions increases, that is, the solution becomes alkaline. So its pH is greater than 7.
Also, according to this theory, acids are those substances that dissolved in water divide H + together with an anion. In this case the pH is less than 7.
But this theory has the disadvantage of being valid only in an aqueous medium. And it does not consider non-protic acids incapable of releasing hydrogenic ions, nor bases incapable of liberating hydroxylic ions.
The correct answer is b. a substance that is a hydrogen ion donor
