Separation of M-toluic Acid, Acetanilide, and NaCl

Discussion

Overall this experiment was a success yielding 98.8% of the initial 1.34g of known compounds. Looking at Table 1 the problem of separation quickly becomes apparent, both M-Toluic Acid and Acetanilide are insoluble in water. This left two non-salts in one mixture, and what solvent to use to separate these two was the most important question as their respective melting points are also very similar. After looking at both compounds and noticing the M-Toluic Acid (Image 2) had an OH group hanging off of it next to a double bond, the H ion on the end would be susceptible to a base. But further investigation showed the large number of hydrogen atoms hanging off the Acetanilide (Image 3) and it was thought that the NaHCO3 would be strong enough to rip the Acetanilide apart.

The advantage of these compounds is they all look vastly different and telling them apart from one another and see if they are disappearing was no problem. This was used this to advantage right away; added water to compounds and saw, as predicted, the NaCl become soluble while the other two compounds remained insoluble. This is where the hypothesized NaHCO3 would dissolve the Acetanilide. Initially frustrated by failure as the solvent failed to perform as predicted, but noticed the M-Toluic Acid rise to the top of the solution, rather than starting over improvisational thought arose and manual separation of the M-Toluic Acid off the top of the solution proved quite successful. Then dried both compounds and weighed them. A parallel experiment using acetone in place of NaHCO3 was also being performed. This dipolar aprotic solvent would have been ideal in this experiment as M-Toluic Acid was soluble in it at a raised temperature but because of time constraints (and high moral after finding 98.8% accuracy) the path was abandoned.

There was plenty of error in this experiment, starting principally with Image 1. In this image the M-Toluic Acid is at the top of the solution and is so because there are small air bubbles beneath it. This suggested there was a reaction between the NaHCO3 and the M-Toluic Acid. This may have resulted in an altered weight for M-Toluic Acid, also when drying the compounds not all of the NaHCO3 would have been removed and would have therefore increased the weight. These errors combined may have actually aided in achieving such an impressive number.