ASSIGMENT 14 D: MAKING DESIGNER CHEMICALS
Investigating chlorination of 2-methylpropan-2-ol
Aim: To produce and purify a sample of 2-chloro-2-methylpropane
Introduction:
Chemical reaction: (CH3)3COH + HCL —> (CH3)3CCl + H2O
Mechanism:
Nucleophilic substitution
Apparatus/ Equipment:
Large 250 cm3 conical flask with bung
100cm3 (or larger) separating funnel with bung.
250cm3 beaker for liquid run out of separating funnel.
Filter funnel to fit separating funnel
Apparatus for distillation with 50 cm3 pear-shaped (or round-bottomed) flask and
thermometer able to read up to 100°C.
25 cm3 and 100 cm3 measuring cylinders
10 cm3 2-methylpropan-2-ol.
35 cm3 concentrated hydrochloric acid.
0.1 mol dm-3 sodium hydrogen carbonate solution.
6g powdered anhydrous calcium chloride.
Anhydrous sodium sulphate.
Small conical flasks with bungs (no bigger than 100 cm 3)
Test tubes
Sample tube
Silver nitrate solution
Dilute sodium hydroxide solution.
Dilute nitric acid.
Spatulas.
5cm3 ethanol.
Bunsen burner.
, Kettle (Prepare water bath).
Risk assessment:
Hazardous chemical or Nature of the Sources of Control Emergency
microorganism being hazards information measures to procedure
used or made, or reduce the risks
hazardous procedure
or equipment.
2-methylpropan-2-ol Flammable and Wear eye Inform you
harmful protection tutor.
Concentrated Corrosive Gloves Keep
hydrochloric acid Lab coat hygiene,
Hydrogen chloride Are toxic and after using
fumes corrosive CLEAPSS the gloves
2-chloro-2- flammable dispose
methylpropane them to the
Calcium chloride Irritant bin.
Glass handling Breakage If any
Spillage problem
Cuts and nicks has
Hot water Burns happened,
like burning
skin then
proceed
with the
first aid kit.
Method:
1. Fill a large conical flask with 10 cm3 2-methylpropan-2-ol and 35 cm3 concentrated
hydrogen chloride. Gently swirl the flask contents.
2. Place the bung in the mouth of the flask. Gently swirl again, then remove the bung to release
the pressure.
, 3. Continue swirling the mixture with the bung fitted and then releasing the pressure for
around 20 minutes. There should be two layers in the flask. The upper layer is the crude
product.
4. Add approximately 6 g of powdered anhydrous calcium chloride to the flask and swirl until it
has dissolved. This ensures that any unreacted alcohol is in the lower aqueous layer.
5. Transfer the reaction mixture to a separating funnel. Allow the mixture to settle into the two
layers. Run off and discard the lower layer. Retain the upper organic layer in the separating
funnel.
6. Add approximately 20 cm3 of sodium hydrogen carbonate solution to the separating funnel.
Swirl the funnel and remove the bung to release the pressure, caused by the production of
carbon dioxide, at frequent intervals. Run off and discard the lower aqueous layer.
Investigating chlorination of 2-methylpropan-2-ol
Aim: To produce and purify a sample of 2-chloro-2-methylpropane
Introduction:
Chemical reaction: (CH3)3COH + HCL —> (CH3)3CCl + H2O
Mechanism:
Nucleophilic substitution
Apparatus/ Equipment:
Large 250 cm3 conical flask with bung
100cm3 (or larger) separating funnel with bung.
250cm3 beaker for liquid run out of separating funnel.
Filter funnel to fit separating funnel
Apparatus for distillation with 50 cm3 pear-shaped (or round-bottomed) flask and
thermometer able to read up to 100°C.
25 cm3 and 100 cm3 measuring cylinders
10 cm3 2-methylpropan-2-ol.
35 cm3 concentrated hydrochloric acid.
0.1 mol dm-3 sodium hydrogen carbonate solution.
6g powdered anhydrous calcium chloride.
Anhydrous sodium sulphate.
Small conical flasks with bungs (no bigger than 100 cm 3)
Test tubes
Sample tube
Silver nitrate solution
Dilute sodium hydroxide solution.
Dilute nitric acid.
Spatulas.
5cm3 ethanol.
Bunsen burner.
, Kettle (Prepare water bath).
Risk assessment:
Hazardous chemical or Nature of the Sources of Control Emergency
microorganism being hazards information measures to procedure
used or made, or reduce the risks
hazardous procedure
or equipment.
2-methylpropan-2-ol Flammable and Wear eye Inform you
harmful protection tutor.
Concentrated Corrosive Gloves Keep
hydrochloric acid Lab coat hygiene,
Hydrogen chloride Are toxic and after using
fumes corrosive CLEAPSS the gloves
2-chloro-2- flammable dispose
methylpropane them to the
Calcium chloride Irritant bin.
Glass handling Breakage If any
Spillage problem
Cuts and nicks has
Hot water Burns happened,
like burning
skin then
proceed
with the
first aid kit.
Method:
1. Fill a large conical flask with 10 cm3 2-methylpropan-2-ol and 35 cm3 concentrated
hydrogen chloride. Gently swirl the flask contents.
2. Place the bung in the mouth of the flask. Gently swirl again, then remove the bung to release
the pressure.
, 3. Continue swirling the mixture with the bung fitted and then releasing the pressure for
around 20 minutes. There should be two layers in the flask. The upper layer is the crude
product.
4. Add approximately 6 g of powdered anhydrous calcium chloride to the flask and swirl until it
has dissolved. This ensures that any unreacted alcohol is in the lower aqueous layer.
5. Transfer the reaction mixture to a separating funnel. Allow the mixture to settle into the two
layers. Run off and discard the lower layer. Retain the upper organic layer in the separating
funnel.
6. Add approximately 20 cm3 of sodium hydrogen carbonate solution to the separating funnel.
Swirl the funnel and remove the bung to release the pressure, caused by the production of
carbon dioxide, at frequent intervals. Run off and discard the lower aqueous layer.
