EXPERIMENT 7: Cannizzaro reaction and reaction of benzaldehyde with ethylene glycol
Introduction: From the first experiment, the reaction of benzaldehyde and potassium hydroxide will produce two products which are benzyl alcohol and benzoic acid. We are going to look at how to get this two products separated by using their different chemical properties. For the second experiment, benzaldehyde ethylene acetal is formed when the reaction done under acidic environment. Through this experiment will show us how to obtain products by using distillation and separation.
Experimental set-up:
Experiment (A): Experiment (B):
(A.1) (B.1) (B.2) (B.3)
PART(A) Cannizzaro reaction:
Procedure:
1) In order to prepare ethanolic …show more content…
6) The organic phase which is the top layer was poured into a beaker right after the lower layer was removed.
7) A teaspoon of potassium carbonate was used to dry the organic phase.
8) The dry organic phase without the potassium carbonate was poured into a 250ml round bottom flask and being distilled again by using the same setup shown in graph(B.1)
9) The solution was boiled until it left 2-3ml(accidentally, as the lab manual indicates 5 to 10ml) and a solvent was distilled into a tall beaker. The solvent was determined by using a Abbe refractometer.
10) The remaining solution was poured into a 100ml flask and the micro-distillation apparatus with an adapter with four flasks was equipped.
11) The product was distilled by using the setup in graph(B.3). When the temperature shown in the thermometer reach 110, four flasks were turning at each 5 degrees Celcius increase interval to retrieve the product distilled in each mini flasks.
12) The refractive index of the product in mini flasks was determined by using the Abbe refractometer.