Net Ionic Equations Continued!

Net Ionic Equations Continued!

NaCl is soluble in water. Solid NaCl dissociates into Na+ and Cl- ions in aqueous solution:NaCl(s) Na+

(aq) + Cl-

(aq)

Pb(NO3)2 + 2NaI PbI2 + 2NaNO3

(aq) (aq) (s) (aq)

See solubility ruleson p 344 of the text

Net Ionic Equations

Balanced Chemical Equation:Pb(NO3)2(aq) + 2NaI(aq) PbI2(s) + 2NaNO3(aq)

“Complete Ionic” Equation:Pb2+

(aq) + 2NO3-(aq) + 2Na+

(aq)+ 2I-(aq) PbI2(s) + 2Na+

(aq) + 2NO3- (aq)

Cancel the “spectator ions” that appear on both sides of the arrow

Pb2+(aq) + 2NO3

-(aq) + 2Na+

(aq)+ 2I-(aq) PbI2(s) + 2Na+

(aq) + 2NO3- (aq)

“Net Ionic” Equation:

Pb2+(aq) + 2I-

(aq) PbI2(s)

Solubility Rules

For the exam: know how to use solubility rules to predict whether an ionic compound is insoluble or not

Net Ionic Equations Revisited:1) Write the (balanced!) molecular equation first

- Reaction products: swap cations and anions- Predict solubility (using Solubility rules)

2) Write the complete ionic equation next- (s) compounds don’t ionize- (aq) compounds do ionizeion subscripts in the molecular equation become

coefficients in the complete ionic equation!

3) Write the net ionic equation next- cancel spectator ions

The net ionic equation is a “simplified” form of the complete ionic equation

Example

Ba(NO3)2 + NiSO4

Balanced Molecular Equation:

Ba(NO3)2 + NiSO4 Ni(NO3)2 + BaSO4

Balanced Molecular Equation:

Example

Ba(NO3)2(aq)+ NiSO4(aq) Ni(NO3)2 (aq)+ BaSO4(s)

Balanced Molecular Equation:

Example

Ba2+(aq) + 2NO3

-(aq) + Ni2+

(aq) + SO42-

(aq)

Ni2+(aq) + 2NO3

-(aq) + BaSO4 (s)

Balanced Molecular Equation:

Complete Ionic Equation:

Example

Ba(NO3)2(aq)+ NiSO4(aq) Ni(NO3)2 (aq)+ BaSO4(s)

Ba2+(aq) + 2NO3

-(aq) + Ni2+

(aq) + SO42-

(aq)

Ni2+(aq) + 2NO3

-(aq) + BaSO4 (s)

Balanced Molecular Equation:

Complete Ionic Equation:

Example

Ba(NO3)2(aq)+ NiSO4(aq) Ni(NO3)2 (aq)+ BaSO4(s)

Ba2+(aq) + 2NO3

-(aq) + Ni2+

(aq) + SO42-

(aq)

Ni2+(aq) + 2NO3

-(aq) + BaSO4 (s)

Balanced Molecular Equation:

Complete Ionic Equation:

Example

Ba(NO3)2(aq)+ NiSO4(aq) Ni(NO3)2 (aq)+ BaSO4(s)

Net Ionic Equation:Ba2+

(aq) + SO42-

(aq) BaSO4 (s)

What is the Net Ionic Equation for the reaction: HCl(aq) + NaOH(aq) ?

HCl(aq) + NaOH(aq) H2O(l) + NaCl(aq)

H+(aq) + -OH(aq) H2O(l)