Esters investigation.

Cool the contents of the flask under running cold water and add 2cm3 of concentrated sulphuric acid drop by drop to the flask, whilst still cooling under the cold tap.

Add 3 or 4 anti-bumping granules to the flask. Attach a water-cooled condenser and set up the apparatus ready to reflux using a micro burner.

Reflux the mixture in the flask for 20 minutes

Rearrange the apparatus for distillation and distil over the fraction that below 80c

Add some anhydrous sodium carbonate to the distillate and mix well. The anhydrous sodium carbonate will react with any ethanoic acid and sulphuric acid in the distillate and neutralise it . it will also remove some of the water present in the distillate.

When you are sure that all the ethanoic acid in the distillate has been neutralised, add some anhydrous calcium chloride should remove any remaining water in the distillate and any ethanol that is still present.

Decant the distillate into a clean 100cm3 round-bottomed flask and distil the mixture.

Collect the fraction that boils between 76c and 78c. This ester.

Determine the mass of ethyl ethanoate that has been collect.

Results.

Mass of beaker

51.84gram

Mass of beaker and ester

67.20gram

Mass of ester

5.72gram

Formula to prepare ester

CH3CO2H + CH2OH ----------------- CH3COCH2CH3

Ethanoic acid ethyl ethanoate

I mole of ethanoic acid produces 1 mole of ethyl acetate

Mass RMM: C= 12*2 = 24

H= 1*4 = 4

O= 16*2=32 +

60

mass RMM: C = 4*12=48

H = 2*4 = 8

O= 16*2=32 +

88

88 x 12gram = 17.6 gram Theoretical yield

60

% Yield = actual yield = ? 100

Theoretical yield

% Yield = 15.72 = x 100 = 89.3%

17.6