TeacherExpt:Sodium ethanoate ‘stalagmite’ From Learn Chemistry
Wiki In this demonstration experiment a supersaturated solution
of sodium ethanoate crystallises rapidly forming a ‘stalagmite’.
This is a demonstration used to show the rapid crystallisation
of a supersaturated solution in a spectacular way and explore
the energy change involved. It can also be used to stimulate
interest in public presentations. Apparatus and chemicals The
teacher requires: - Eye protection - Beaker (250 cm3) -
Measuring cylinder (25 cm3) - Watch glass (large one, about 10
cm diameter) - Stirring rod - Bunsen burner, tripod and gauze -
Access to a top-pan balance (1 d.p. is sufficient) - A black
background is probably better than a white one for this
demonstration. - The ‘stalagmite’ can be re-heated and used
again. Keep the solution clean and free from dust – this could
cause it to crystallise prematurely. Health & safety Wear eye
protection throughout. Before the demonstration: B. Heat the
beaker over a low flame and stir until