Volumetric Analysis Lab Report Conclusion

The two main purposes of the lab were to determine the percent by mass of acetic acid in vinegar and to determine the molar concentration of a strong acid. In both parts of the experiment a volumetric analysis was used. This is primarily the aid of volumetric glassware in order to determine specific measurements and calculations. Potassium hydrogen phthalate was used as the primary acid standard to determine the molar concentration of the sodium hydroxide solution in part one of the experiment. It was known that the potassium hydrogen phthalate and sodium hydroxide should have had a 1:1 stoichiometric molar ratio. Potassium hydrogen phthalate was used as the primary standard because it is a very pure concentrated substance that can be predicted. However, the sodium hydroxide is too difficult to be measured because of its tendency to absorb water vapor. This is one area where error can be noted; at times the sodium hydroxide was exposed to an open atmosphere where it could have absorbed water vapor from the lab. In table 1, the molar concentrations should have all equaled 0.1 mol/L. In this case it did not, trials one, two and three averaged about .2026 mol/L, the concentration of sodium hydroxide was too high. As stated this could have been from exposure to the atmosphere, or too much NaOH may have been added. It became very difficult to operate …show more content…
Table 1 shows a standard deviation of only .0049, which is typically great, except their values should have all been the same in this case. In table 2 the average percent by mass came out to .54% of acetic acid, which was much lower than expected. It was given that the percent of acetic acid should have come out to about 4%. Again, in this lab the same errors could have led to this conclusion. Too much sodium hydroxide was added, which lead to the acetic acid levels being too