Precipitation Reactions

Common Ion Effect

The addition of concentrated hydrochloric acid to a saturated solution of sodium chloride causes solid sodium chloride to precipitate out.

Fehling Test

When blue Fehling's reagent is added to glucose and fructose solution a brick-red precipitate forms - no rxn with sucrose.
Fehling Test

Zinc Complex Ion Formation

Zinc ion is precipitated by sodium hydroxide. The addition of more hydroxide redissolves the precipitate.

What's In A Name?

Potassium chloride is contrasted potassium chlorate to illustrate the importance of nomenclature details.
Gummi Destruction!

Copper-Ammonia Complex

Copper chloride solution forms a pale blue precipitate then a deep blue solution as ammonia is added.
Copper Hydroxide

Aldol Clock

A solution of cinnamaldehyde and acetone suddenly turns bright yellow after induction period.
Aldol Clock


© Copyright 2012 Email: Randy Sullivan, University of Oregon Chemistry Department and UO Libraries Interactive Media Group