Demonstration of Chloroform
Chemicals needed
Distilled water
Chloral hydrate T R 25-36/38 S (1/2)-25-45
Sodium hydroxide solution 20% C R 35 S (1/2)-26-37/39-45
Dangerous substance information
Trichlormethane Xn R 22-38-40-48/20/22 S (2)-36/37
Equipment needed
Pear shaped flask (alternative: test tube) with plug
Test procedure
- Safety goggles! Bear in mind toxicity!
- 3 g chloral hydrate is placed in the flask, this is dissolved with a constant swaying motion in 5 ml water.
- Add 2 ml half-concentrated sodium hydroxide solution, plug, under intermittent airing shake a couple of times.
- Left standing the chloroform will settle to the bottom as a colorless, clear, heavy liquid. One can remove some with a pipette and test the smell (very carefully!).
Disposal
- Both phases should be disposed of as halogenated organic waste. The chlorofom can, of course, be kept for other experiments (labelling!)
Elucidation
Due to base catalysis choral hydrate is decomposed into chloroform and formic acid.
CCl3CH(OH)2--> CHCl3 + HCOOH
Photos
Chloroform precipates.
Literature
derived from experiment 1643S, "Chloroform ausChloral", S. 300, [2]