Demonstration of ethyl acetate

Chemicals needed

acetic acid 99% C     R 10-35    S (1/2)-23-26-45

ethanol  F    R 11    S (2)-7-16

or alcohol

sulphuric acid 96 %  C    R 35   S (1/2)-26-30-45

The acetic acid should be as concentrated as possible (glacial acetic acid).

Dangerous substance information

ethyl acetate  F Xi    R 11-36-66-67     S (2)-16-26-33

Equipment needed

2 test tubes (1 normal, 1 small)
rubber plugs with hole and discharge tube
stand with double sleeve and clamp
beaker or the like
burner (preferably alcohol)

Test procedure

• Safety goggles! Pay attention to danger of fire.
• Add to the (normal) test tube 2 ml ethanol and 1 ml acetic acid, then add approx. 0.5 ml concentrated sulphric acid.
• Carefully sway the mixture back and forth. If this is not done, the mixture will at the beginning boil with eructation.
• Clamp the test tube steeply or vertically to the stand, apply the plug with discharge tube, such that the discharge tube leads into a test tube, which is in a beaker with cold water. In order to avoid recoil the discharge tube should discharge a goodly distance from the bottom.
• Warm the mixture with the burner and keep it boiling slightly. Do not heat too strongly, the mixture will at the beginning continue to boil on its own for several seconds. Once nearly half of the mixture has been distilled off, terminate the heating. A clear distillate has been produced. Before opening the apparatus extinguish the flame.
• The product is, as one can easily verify, scarcely soluble and lighter than water. It has a characteristic smell, which reminds one of Uhu (at least like it used to be...).

Disposal

• The reaction mixture is carefully merged with much water and then dischargen into the drainage.
• One can dispose of the product as halogene-free organic waste.

Elucidation

Esterification is a balance reaction. Through the dehydrating effect of concentrated sulphuric acid and the distilling off of the product the balance is shifted in the desired direction. This procedure is naturally only successful with esters which are markedly more volatie than carboxylic acids and alcohol. For formic acid one may not use them! (Wonder why?)

Photos

Apparatus before the begin of distillation.

Literature

Self-derived method modelled after a school experiment.