Determination of the equilibrium constant for an Esterification reaction.

Authors Avatar

Determination of the equilibrium constant for an Esterification reaction

Evaluation of the Experiment (Skill E)

Overall, I feel that the accuracy of the result was quite good. Because the equilibrium constant is a constant, the value of Kc should be the same for each experiment. All of the Kc values calculated for the four experiments came to approximately 6 (no units). The results are summarised below.

We can see from these results that although the value of Kc is roughly the same for all of them it is quite small for experiment one. I believe that this is an anomalous result.

There were two main areas of limitation in this experiment. The first concerns the fact that the temperature of the experiment was not reliably regulated. Kc is not affected by a change in concentrations because the concentrations at equilibrium will always remain in the same proportions so Kc remains the same. However Kc does change with temperature. It is difficult to maintain the temperature at room temperature because this is continually changing by small but significant degrees. These slight changes meant that each experiment could potentially have been conducted at a slightly different temperature resulting in different values of Kc.

Join now!

The second limitation is that the experiment did not take place in a closed system. Sodium hydroxide (NaOH) was added externally. Because the temperature was quite high the reaction was still proceeding. This means that the NaOH neutralised the acid in the equilibrium. Removing the acid caused a shift in the equilibrium to make more acid. This again makes our value of Kc quite unreliable because on adding the NaOH we have actually shifted the equilibrium.

There were two main sources of error of measurement in the experiment. These came from taking measurements using the burette and pipette.


This is a preview of the whole essay