Práctica de laboratorio TSQ

UNIVERSIDAD AUTÓNOMA DE NUEVO LEÓN[pic 1][pic 2]

PREPARATORIA 7

CHEMISTRY SELECTED TOPICS

STAGE 1     PRACTICE 1

ELABORATION OF A SYNTHETIC AROMA "ESTERIFICATION"

STUDENT:_____________________________________________________________ GROUP:_________

TEACHER:________________________________________________ DATE:____________________

A) INTRODUCTION:

 In general, esters are volatile compounds that have characteristic strong odors. Odors and natural fragrances are often mixtures of esters and other derivative compounds, while artificial flavorings generally contain few compounds and the taste may not be the same as natural, however, synthetic flavors and quality flavors can be obtained if they adequately control the reaction conditions. This type of synthesis is widely used today by the food processing industry and sweets.

Esters are derivatives of carboxylic acids in which the -OH group of the carboxyl group has been replaced by an -OR of an alcohol. In this practice you will test experimentally the esterification reaction used as a source of obtaining synthetic aromas.

B) Research tasks:

Prior to the experimental work, answer the following tasks.

1.- Write the functional group characteristic of the esters.

2.- Investigate and report some physical and organoleptic properties of isoamyl acetate.

3.- Write the structure of isoamyl acetate.

4.- Investigate which acid and which alcohol combine and produce isoamyl acetate.

5.- Write the equation representing the formation reaction of isoamyl acetate.

C) Materials and reactants:1 test tube, Tube clamps, Rack, 400 ml beaker, 50 ml beaker. Lighter, tripod and asbestos cloth, Container with ice and water.

Reactants: Isopropyl alcohol, Acetic acid, and chloridric acid.

D) Experimentation: 1. Place 3 ml of isopropyl acid in the test tube. 2.- Add 3 ml of acetic acid and 0.5 ml (10 drops) of sulfuric acid as a catalyst.

3.- Add water to the beaker halfway and place it on the asbestos cloth and the burner. 4.- place the test tube with the mixture inside the glass with water and heat for 3 minutes.

5.- Take the tube with the tweezers and place it in a container with water and ice. 6.- Direct the smell of the liquid towards your nose with the palm of your hand and write down your observations.

E) Interpretation of results

1.- What is the smell of the organic product obtained in this synthesis?

2.- Write the name and structure of the formed product.

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