Topic 12 - Titration curves and buffers

• Carbon dioxide dissolved in the blood forms carbonic acid (H2CO3), so this concentration increases.

• The equilibrium will shift to the right and produces more H+ acid ions.

• The high concentration of hydrogencarbonate ions suppress the ionisation of carbonic acid to help control PH. / Excess hydrogencarbonate ions combine with H+ ions to help control blood PH.

Calculate PH of a buffer solution, using Ka.

• Calculate amount of salt formed, initial amount of acid and amount of acid left.

• Total volume.

• Salt (concentration) = mol salt/ volume, acid (concentration) = mol acid left/ volume.

• H+ = ka * (acid/salt)

• PH = -log H+

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