Identifying a Component of Panacetin

Introduction:

In this lab we will be identifying the unknown compound we previously recovered from Panacetin. The unknown component has been identified as either acetanilide or phenacetin, both comin chemical relatives of acetaminophen. Our experiment today will show us which compound is our unknown component of Panacetin.

Observations:

When the unknown component was finished dissolving and slowly cooled at room temperature and later with ice water the component began to crystallize. After the compound was crystallized the unknown compound was separated into three different groups to measure boiling points. Since the boiling points of phenacetin and acetanilide are different we then added the two compounds to two different groups of the crystallized unknown and left the third group of the unknown alone. While measuring boiling points it was observed that the boiling point of the purified unknown was closest to phenacetin with boiling points respectively at 135 and 130. After the capillary tubes were taken out of the heating instrument the components of each tube slowly resolidified.

Data:

Amount of unknown compound at the start of the experiment: .18g.

Total amount of water added during the dissolving process: 14.75 mL.

Boiling point of purified unknown: 135º C.

Boiling point of phenacetin: 130º C.

Boiling point of acetanilide: 120º C.

Results:

While measuring boiling points it was observed that the boiling point of the purified unknown was closest to phenacetin with boiling points respectively at 135º C and 130º C. The boiling point of acetanilide was measured at 120º C. These results indicate that the purified unknown component of Panacetin is phenacetin.

Discussion:

During the lab no human errors occurred. All of the results received were as first hypothesized in the beginning of the experiment.

Exercises:

The minimum volume of water necessary to dissolve .200 g of phenacetin is 16.39 mL of water. After the water is cooled to room temperature there should be a substantial amount of phenacetin that is still dissolved. In fact, only about 6 % of the phenacetin will no longer be dissolved. This means that only about .01244 g of the original phenacetin can be recovered when the cooled solution is filtered. While looking at identifying unknown compounds as in exercise 2 we must compare the unknown component's boiling point when we add all of the potential compounds it may be to the unknown compound. In the scenario we are given