For a saturated solution of #AgNO_3(aq)#, what will be the effects of: (i) addition of silver nitrate salt; (ii) addition of nitric acid; (iii) addition of silver perchlorate...?

1 Answer
Feb 4, 2017

We examine the equilibrium:

#AgNO_3(s) rightleftharpoons Ag^+ + NO_3^-#


#"Le Chatelier's principle"# states that when a system at equilibrium is subject to an external perturbation, the equilibrium will move so as to offset the external perturbation (#"offset "!=" counteract"#).

Addition of solid silver nitrate will have NO effect on the equilibrium in that the solid does not really participate in the equilibrium reaction. Silver nitrate is assumed to be saturated.

Addition of nitric acid adds #NO_3^-# to solution. The equilibrium will move so as to offset the external perturbation, and move to the LEFT as written. And thus addition of nitric acid should cause precipitation of silver nitrate.

Addition of silver perchlorate, i.e. another SOLUBLE silver salt, to the saturated solution increases the concentration of #[Ag^+]#...and the equilibrium will move to the left as written...and silver nitrate should precipitate.

For another example of #"Le Chatelier's principle"# in practice, see this old answer,