· Planning (a), Planning (b), Data Collection, Data Processing and Presentation, Conclusion and Evaluation

Planning (a): To investigate the factors affecting Ka of a weak acid

The acidity of an acid is determined by the dissociation of H+ ions in the acid, ie the higher it dissociates the more acidic. In other words, the concentration is not a factor affecting the acidity, but the degree of dissociation.

As the dissociation is at equilibrium for all acids, factors such as temperature should have an effect of shifting the equilibrium position, ie temperature affects the degree of dissociation.

e.g.

If temperature increases I suspect [H+] will increase because the equilibrium will shift to the left (dissociation of ions is endothermic) as temperature increases. So temperature is one factor to investigate.

Since the formula of pH is, pH is affected by [HA], meaning the concentration of acid determines...