Seven Steps to a Net Ionic Equation

SEVEN STEPS TO A NET IONIC EQUATION

EXAMPLE: KCl(aq) + Pb(NO3)2(aq) (

1. a. Take only one of the first cation(s) and match it with one of the second anion(s). (Write the cation first) b. Take only one of the second cation(s) and match it with one of the first anion(s). (Write the cation first)

KCl(aq) + Pb(NO3)2(aq) ( KNO3 +PbCl

2. Correct the formulas of the products based on the charges of the ions.

KCl(aq) + Pb(NO3)2(aq) ( KNO3 +PbCl2 ◄

3. Balance the equation

2 KCl(aq) + Pb(NO3)2(aq) ( 2 KNO3 +PbCl2

4. Consult the solubility rules and assign the correct state symbol annotations. This should agree with any observations concerning the formation of a precipitate which gets the symbol (s). If water is formed, water is a molecule; it does not ionize to any significant extent. It is annotated (l).

2 KCl(aq) + Pb(NO3)2(aq) ( 2 KNO3(aq) ◄ +PbCl2(s) ◄

5. Write the Total Ionic Equation(T.I.E.). All compounds that are annotated (aq ) break up into individual cations and anions in that order.

2 K+(aq) + 2Cl-(aq) + Pb2+(aq) + 2NO3- (aq) ( 2 K+(aq) +2 NO3-(aq) +PbCl2(s)

6. Eliminate spectator ions. Spectator ions are in the same form on each side of the equation arrow.

2 K+(aq) + 2Cl-(aq) + Pb2+(aq) + 2NO3- (aq) ( 2 K+(aq) +2 NO3-(aq) +PbCl2(s)

7. Write the Net Ionic Equation (N.I.E.). The convention is to write the cation first followed by the anion on the “reactants” side.

Pb2+(aq) + 2Cl-(aq) ( +PbCl2(s)

Note that chemical equations are written using the lowest common coefficients.
If your NIE ended up as 2 H+(aq) + 2 OH-(aq) ( 2 H2O(l)
It would become H+(aq) + OH-(aq) (