Purification of an Impure Acetanilide Sample by Recrystallization and Determination of Purity by Melting Point

vPURIFICATION OF AN IMPURE ACETANILIDE SAMPLE BY RECRYSTALLIZATION AND DETERMINATION OF PURITY BY MELTING POINT

A lab report by Andrea Maurene Manuel and Den Clea Ross Tuazon of LBYCH30-A51

ABSTRACT

RRL

RESULTS/DISCUSSION

CONCLUSION/RECOMMENDATION

REFERENCES

APPENDIX

Questions:

1. Among the following solvents-water, acetone, ethanol, and toluene, which one was observed to be most suitable for recrystallization of acetanilide? Why?

The most suitable solvent for the recrystallization of acetanilide is water because it can cause the acetanilide to be more soluble especially in hot water.

2. Why was a water bath used instead of direct heating in the choice of solvent?

A water bath was used instead because directly heating could evaporate the solvent. Direct heating can also cause the solvents to catch fire.

3. Why was activated charcoal added into the mixture of acetanilide, sodium chloride and congo red? What is adsorption?

Activated charcoal was used because it can increase the surface area available for adsorption. Adsorption is the process when solid, liquid, or gas adheres to a surface or thin layer.

4. Would it be wrong to dissolve the original impure material in a large excess of solvent? Why?

Yes it is wrong because the crystals will not form if it is in a large excess of solvent.

5. In gravity filtration, what is the advantage of using a short-stemmed funnel over a long-stem funnel?

Using a short-stemmed funnel is more advantageous compared to using a long-stemmed funnel because there is a chance for the product to recrystallize within the stem.

6. Why were the funnel and the flask preheated before filtering the impure acetanilide?

The funnel and flask must be preheated so that the solution would pass through without cooling