07. T.A. Michael Hall
Alkanes: Chlorination
Introduction:
The purpose of this experiment is to determine the reactivity of hydrogen atoms on a carbon chain using free radical chlorination. In this experiment 1-chlorobutane will be chlorinated with the combination of sulfuryl chloride and ABCN as an initiator to produce the chlorine radicals. The combination of 1-chlorobutane and sulfur chloride will produce four dichlorobutane isomers. The isomers produced and their reactivity will be analyzed by the amounts of isomers produced in the product and by gas chromatography.
Procedure:
1) Assemble the apparatus in the hood using a Thermowell Heater 2) Use a 25-mL round bottom flask fitted with a reflux condenser which will be connected through a vacuum adapter to a 500-mL filter flask. a. close vacuum adapter w/ cork and make sure the inlet tube does not reach the surface of the water in the filter flask b. make sure any water from the trap does not get sucked back into the reaction flask c. glass tube must not dip below the surface of the water in the trap 3) Note the differences on pg.77 of G&M fig. 2.65(b) a. it does not use a water aspirator or house vacuum b. Fit #7 one-hole rubber stoppers w/ a length of glass tubing about 15cm long. c. Tubing needs to be fire-polished on both ends and lubricate hole in stopper with glycerin. d. Use cloth towel to protect your hands as you insert the tubing into the stopper and wipe off excess glycerin. 4) Add stirbar, .1g of 2,2-azobis(cyclohexanenitrile), 5mL of 1-chlorobutane and 2-mL of sulfuryl chloride and place in flask 5) Stopper and weigh. Then hook flask to reflux condenser 6) Heat solution for 20 minutes, let cool below reflux temperature and check weight. If the weight loss is not enough continue to next step