3D GRIDBUILDING - SCIENCE - CHEMISTRY

PRECIPITATE

A precipitate is a solid which forms within a solution as a result of a chemical reaction or physical process and which, because it is denser than the solution, does not stay in suspension within it.


For example, if we add a solution of silver nitrate (AgNO₃) to a solution of potassium chloride (KCl) - both of which are colourless - in a test tube, we will observe a white solid forming, which quickly settles to the bottom of the test tube.


This is because the two compounds react, and one product of the reaction, silver chloride, is insoluble and also dense enough to "precipitate out" of the solution.


The full chemical equation is as follows:

AgNO₃(aq) + KCl(aq) —→ AgCl(s) + KNO₃(aq)


Examples of physical processes which can produce precipitates include evaporation.


Anne Evans