Question

All of the following can be used to define an acid except

a hydrogen ion donor in a reaction

a substance that increases the hydronium ion concentration of a solution

an electron-pair acceptor in a reaction

a substance that increases the hydroxide ion concentration of a solution

Answer 1

Answer: a substance that increases the hydroxide ion concentration of a solution

Step-by-step explanation: According to Arrhenius concept, an acid is a substance which donates hydronium ions
`[H^+]` ions when dissolved in water and base is a substance which donates hydroxide ions
`[OH^-]` ions in water.

According to the Bronsted Lowry conjugate acid-base pair, an acid is a substance that donates protons and a base is a substance that accepts protons.

According to Lewis concept, an acid is the substance which accepts electron pairs and abase is a substance which donates electron pairs.

Thus a substance that increases the hydroxide ion concentration of a solution is an Arrhenius base.