Question

Distinguish between acids and bases using Arrhenius, Bronsted-Lowry, and Lewis Theory

a) A molecule which can behave as both an acid and a base is said to be amphoteric. Using the Bronsted-Lowry definitions of acid and base, show that methylamine has amphoteric properties

Answer 1

The Arrhenius Theory of acids and bases

The theory

• Acids are substances which produce hydrogen ions in solution.

• Bases are substances which produce hydroxide ions in solution.

Neutralisation happens because hydrogen ions and hydroxide ions react to produce water.

The Bronsted-Lowry Theory of acids and bases

The theory

• An acid is a proton (hydrogen ion) donor.

• A base is a proton (hydrogen ion) acceptor.

The Lewis Theory of acids and bases

This theory extends well beyond the things you normally think of as acids and bases.

The theory

• An acid is an electron pair acceptor.

• A base is an electron pair donor.