Write what is in the purple boxes Aqueous Solutions Write what is in the purple boxes

Ionic Equations An aqueous solution is ions dissolved in water When a soluble substance is dissolved in water, the substance often breaks into ions. This solution is said to be an aqueous solution. Pb(NO3)2(aq)  Pb2+(aq) + 2NO3-(aq) NaI(aq)  Na+(aq) + I-(aq) An aqueous solution is ions dissolved in water

Ionic Equations Consider the reaction… What is really going on is… Pb(NO3)2(aq) + 2NaI(aq)  PbI2(s) + 2NaNO3(aq) What is really going on is… Pb2+ + 2NO3- + 2Na+ + 2I-  PbI2(s) + 2Na+ + 2NO3- Note that the Na+ ion and the NO3- ion are not reacting. They are said to be spectator ions.

Net Ionic Equations It is often useful to write an equation showing only the species that are actually reacting. This is called a net ionic equation. It does not show the spectator ions. Pb2+ + NO3- + Na+ + 2I-  PbI2(s) + Na+ + NO3- becomes…. Pb2+(aq) + 2I-(aq)  PbI2(s)

Precipitates The solid formed from mixing two aqueous solutions is called the precipitate

To predict precipitates, use the Precipitation Diagram A solid box means a solid forms

Examples NaOH(aq) + Cu(NO3)2(aq)  Na3PO4(aq) + Fe(NO3)3(aq)  MgSO4(aq) + AgNO3(aq)  KOH(aq) + NaNO3(aq) 