Question

Which of the following statements is not true regarding acids? (3 points)

Arrhenius acid is any substance that increases the concentration of hydronium ions.

Brønsted-Lowry acid is any substance that donates a hydrogen ion.

Lewis acid is a substance that donates a lone-pair of electrons.

The pH is less than 7.0.

Answer 1

Answer : The incorrect statement is, Lewis acid is a substance that donates a lone-pair of electrons.

Explanation :

According to the Arrhenius theory, an acid is a substance that ionizes in the water to give hydronium ion
`(H_3O^+)` or hydrogen ion
`(H^+)` and a bases is a substance that ionizes in the water to give hydroxide ion
`(OH^-)`.

According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.

According to the Lewis acid-base theory, an acid is a substance that accepts pairs of electrons and the a base is a substance that donates pairs of electrons.

The pH of an acid is always less than 7.

Hence, the incorrect statement is, Lewis acid is a substance that donates a lone-pair of electrons.

Answer 2

Lewis acid is a substance that donates a lone-pair of electrons.

Step-by-step explanation:

What is said in the statement corresponds to a Lewis base, not an acid. For example, NH3 is a Lewis base, since it is capable of donating its pair of electrons. Trimethylborane (Me3B) is a Lewis acid, since it is capable of accepting a solitary pair.