Making soap: saponification of an oil
Ten grams of olive oil, twenty millilitres of ethanol and an excess of sodium hydroxide go into a round-bottom flask under a condenser. Half an hour at reflux turns the oil into glycerol and soap. Salting out in brine makes the soap solid, and a Büchner filter collects it.
Loading the laboratory
Each step has a button in the rail; the bench makes the gesture. You can also grab the bottle and carry it yourself. Click a name or an object to look closer, double-click the bench to step back. Slide the view with shift + scroll, the arrow keys, a right-button drag or two fingers.
Step 1 of 15
- 1Get ready
Goggles, gloves and lab coat: this bench has concentrated sodium hydroxide and hot ethanol.
- 2Set up the reflux
- 3Charge the flask
- 4Predict what heating will do
- 5Heat to reflux
- 6What is happening?
- 7Let it reflux
- 8Read the temperature
- 9Why reflux?
- 10Salt the soap out
- 11What happened in the brine?
- 12Filter on the Büchner
- 13Weigh the soap
- 14Why did it work?
- 15Soap made