Net Ionic Equations Continued!
Jan 11, 2016
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)