1.6. Buffering systems

What is a buffer system?

A system that resists large pH changes.

ie. the solvent from getting too acidic OR too basic from a certain range.

This uses either a weak acid or base, and their conjugate counterparts.

Explain how an buffer solution resist addition of a strong acid?

• When a strong acid is added, the strong acid will react with the conjugate base.

• This will shift the buffer system to the left to counteract the addition of H3O+

• therefore using it up H3O+. Therefore the pH remains steady.

Explain how a buffer solution resist addition of a strong base?

• The buffer will counteract by reacting the weak acid with the strong base.

• The hydrogen in the weak acid will PROTONATE the OH- and turn it into water.

• this essentially removes OH-.

Why can only weak acids and bases form buffers?

Because they partially dissociate and the difference in concentrations mean the equlibrium can easily shift.

CH₃COOH  +   H₂O   ⇌  CH₃COO^- + H₃O⁺

1. Explain what would happen if acid is added to this using LCP.

2. Explain what would happen if base is added to this using LCP.