How do to measure the solubility of a solid?

1 Answer
Feb 28, 2018

The solubility of a compound can be measured using the solubility product constant, or #K_(sp)#.

Explanation:

The following equation shows the dissolution of #AgCl# in water.

#AgCl_((s))->Ag_((aq))^++Cl_((aq))^-#

The solubility product expression can be written like this:

#K_(sp)=[Ag^+][Cl^-]#

The solid #AgCl# is not included, because solids are not included in equilibrium expressions.

The #K_(sp)# value for #AgCl# is about #1.77*10^-10#:

#K_(sp)=[Ag^+][Cl^-]=1.77*10^-10#

This means that if the concentration of #Ag^+# and #Cl^-# ions in a solution exceed #1.77*10^-10# when multiplied together, solid #AgCl# will precipitate out of the solution.