Emilia Hawkins
Unit 4: Laboratory Techniques and their Application
B: Explore the manufacturing techniques and testing methods for an organic liquid.
Preparation of an ester (ethyl ethanoate)
CH₃COOH + CH₃CH₂OH > CH₃COOH₂CH₃ + H₂O
ethanoic acid + ethanol > ethyl ethanoate + water
acid + alcohol > ester + water
Hypothesis
Esters are formed when acid and alcohols react in the presence of a strong-acid catalyst. This
experiment aims to determine the percentage yield of ethyl ethanoate produced under laboratory
conditions.
Aim
The aim of the experiment is to prepare an ester (ethyl ethanoate) by reacting ethanoic acid and
ethanol in the presence of a catalyst (sulfuric acid) using reflux and distillation.
Equipment
Quickfit apparatus, clamp, stand, measuring cylinder, flask, scales, disposable pipette, electric
heater, beaker, spatula, anti-bumping granules, water supply.
Ethanol, ethanoic acid, concentrated sulfuric acid, sodium carbonate, calcium chloride.
Risk Assessment
Goggles and lab coats must be worn. If any of the chemicals are spilt on the skin, wash with plenty of
water. Gloves must be worn when handling pure ethanoic acid and concentrated sulfuric acid as
they are corrosive and may cause harm if it is spilt on the skin.
Any organic waste products must be put in the fume cupboard and not down the sink as they are
harmful to the environment.
Having an open flame around organic solvents is dangerous because they are flammable; an electric
heater should be used to prevent combustion.
Apparatus is made out of glass and could break if dropped, therefore care has to be taken when
handling the equipment.
Method
, Emilia Hawkins
Part 1: heating the reaction mixture under reflux
o Remove the condenser from the apparatus.
o Weigh a measuring cylinder containing 5 cm³ of ethanol and then add this to the flask.
o Reweigh the measuring cylinder to determine the exact mass of ethanol used.
o Wearing gloves, use a measuring cylinder to add 6 cm³ of pure ethanoic acid to the flask.
o Wearing gloves, use a disposable pipette to measure 1 cm³ of concentrated sulfuric acid and
add it slowly to the mixture in the flask.
o Add anti-bumping granules, refit the condenser and turn on the water supply.
o Gently heat the flask using an electric heater until it boils. Continue heating the mixture for
10 minutes to complete the reaction.
o Remove the heat and allow the apparatus to cool to room temperature.
o Remove the condenser from the cooled reaction flask and add small amounts of sodium
carbonate solution until the mixture no longer fizzes.
Part 2: isolating the product by distillation
o Turn in the water supply.
o Heat the flask gently; the liquid should start to distil over.
o Collect the liquid that distils at up to 80°C.
o When the temperature goes above 80°C, or drops completely, stop heating and replace the
collection flask with another beaker to collect any further unwanted distillate.
o Allow the apparatus to cool and dismantle.
o Add a small spatula of calcium chloride to your distillate to remove the water.
o Weigh a small (50 cm³) beaker and decant your distillate leaving the calcium chloride behind.
o Reweigh your beaker and determine the mass of ethyl ethanoate produced.
o Calculate the atom economy and % yield of the process based on the starting mass of
ethanol.
Unit 4: Laboratory Techniques and their Application
B: Explore the manufacturing techniques and testing methods for an organic liquid.
Preparation of an ester (ethyl ethanoate)
CH₃COOH + CH₃CH₂OH > CH₃COOH₂CH₃ + H₂O
ethanoic acid + ethanol > ethyl ethanoate + water
acid + alcohol > ester + water
Hypothesis
Esters are formed when acid and alcohols react in the presence of a strong-acid catalyst. This
experiment aims to determine the percentage yield of ethyl ethanoate produced under laboratory
conditions.
Aim
The aim of the experiment is to prepare an ester (ethyl ethanoate) by reacting ethanoic acid and
ethanol in the presence of a catalyst (sulfuric acid) using reflux and distillation.
Equipment
Quickfit apparatus, clamp, stand, measuring cylinder, flask, scales, disposable pipette, electric
heater, beaker, spatula, anti-bumping granules, water supply.
Ethanol, ethanoic acid, concentrated sulfuric acid, sodium carbonate, calcium chloride.
Risk Assessment
Goggles and lab coats must be worn. If any of the chemicals are spilt on the skin, wash with plenty of
water. Gloves must be worn when handling pure ethanoic acid and concentrated sulfuric acid as
they are corrosive and may cause harm if it is spilt on the skin.
Any organic waste products must be put in the fume cupboard and not down the sink as they are
harmful to the environment.
Having an open flame around organic solvents is dangerous because they are flammable; an electric
heater should be used to prevent combustion.
Apparatus is made out of glass and could break if dropped, therefore care has to be taken when
handling the equipment.
Method
, Emilia Hawkins
Part 1: heating the reaction mixture under reflux
o Remove the condenser from the apparatus.
o Weigh a measuring cylinder containing 5 cm³ of ethanol and then add this to the flask.
o Reweigh the measuring cylinder to determine the exact mass of ethanol used.
o Wearing gloves, use a measuring cylinder to add 6 cm³ of pure ethanoic acid to the flask.
o Wearing gloves, use a disposable pipette to measure 1 cm³ of concentrated sulfuric acid and
add it slowly to the mixture in the flask.
o Add anti-bumping granules, refit the condenser and turn on the water supply.
o Gently heat the flask using an electric heater until it boils. Continue heating the mixture for
10 minutes to complete the reaction.
o Remove the heat and allow the apparatus to cool to room temperature.
o Remove the condenser from the cooled reaction flask and add small amounts of sodium
carbonate solution until the mixture no longer fizzes.
Part 2: isolating the product by distillation
o Turn in the water supply.
o Heat the flask gently; the liquid should start to distil over.
o Collect the liquid that distils at up to 80°C.
o When the temperature goes above 80°C, or drops completely, stop heating and replace the
collection flask with another beaker to collect any further unwanted distillate.
o Allow the apparatus to cool and dismantle.
o Add a small spatula of calcium chloride to your distillate to remove the water.
o Weigh a small (50 cm³) beaker and decant your distillate leaving the calcium chloride behind.
o Reweigh your beaker and determine the mass of ethyl ethanoate produced.
o Calculate the atom economy and % yield of the process based on the starting mass of
ethanol.
