Chapter 6, Lesson 8 Multimedia

Proton Transfer in Water

• The hydrogen atom in the water molecule has one proton and an electron that it shares with the oxygen atom. A proton from a hydrogen atom can transfer to another water molecule, creating the ions H₃O⁺ and OH^-.
• A proton from the H₃O⁺ ion can be transferred to the OH^-, creating water molecules again.

Water Molecules Trade Protons

• The hydrogen atom in the water molecule has one proton and an electron that it shares with the oxygen atom. A proton from a hydrogen atom can transfer to another water molecule, creating the ions H₃O⁺ and OH^-.
• A proton from the H₃O⁺ ion can be transferred to the OH^-, creating water molecules again.

Acids Donate Protons

An acid added to water donates protons to the water molecules. This increases the concentration of H₃O⁺ ions. The H₃O⁺ ions donate protons to the indicator molecules which results in a color change.

Bases Accept Protons

A base added to water accepts protons from the water molecules. This increases the concentration of OH^- ions. The H₃O⁺ ions and the indicator molecules donate protons to the OH^- ions. This decreases the concentration of H₃O⁺ ions and results in a color change.