Experiment #20: Temperature Change and equilibrium
Jeeyoon Kong, Alla
Experiment #20 Lab Report
Temperature change and equilibrium
In this experiment, we will find out how the variation of the value of an equilibrium constant with temperature can be used to determine the enthalpy (heat), entropy (randomness), and free energy (G) changes associated with the system in question.
Materials: 125mL flasks (5), 100mL beaker (1), hotplate, graduated cylinder, stir rod, borax, water, thermometer, pipet, bromcresol green, distilled water, 0.5M HCL solution, titrating kit (stand and buret)
1) Five clean…show more content… As with many experiments that are performed in a setting where we cannot be exact on every measurement, error could arise from it. For instance, from this particular experiment, we needed to measure 5mL of water and 5mL of the borax mixture after it had cooled. Measuring 5mL with the bulb pipet that we were provided was not an exact measurement tool. The pipets provided were not calibrated and/or could have contained pockets of air with the assumed 5mL of water or solution. We can also take into account the factor of temperature difference between the mixture of borax and the crystallized borax which had settled on the bottom of the 100mL beaker. From what I have gathered during this experiment, crystallized borax was warmer than the solution above it. This is something that could greatly vary the results of an experiment as we could have pipetted 5mL of what we believed was 45*C solution but in actuality could have been much different due to incorrect temperature measurement. Another source of error could have been from accidental pipetting of some borax crystals while retrieving 5mL of the solution. This is especially apparent in our two last titrations at 35*C and 30*C. At these temperatures, most of the solution which remained on top of the borax crystals were already