Types of chemical equations :
Types of chemical equations Equations can be divided into 3 types (pg. 333)
1) Molecular, 2) Ionic, 3) Net ionic
Here is a typical molecular equation:
Cd(NO3)2(aq) + Na2S(aq) ? CdS(s) + 2NaNO3(aq)
We can write this as an ionic equation (all compounds that are (aq) are written as ions):
Cd2+(aq) + 2NO3–(aq) + 2Na+(aq) + S2–(aq) ? CdS(s) + 2Na+(aq) + 2NO3–(aq)
To get the NET ionic equation we cancel out all terms that appear on both sides: Net: Cd2+(aq) + S2–(aq) ? CdS(s)
Equations must be balanced :
Equations must be balanced There are two conditions for molecular, ionic, and net ionic equations
Materials balance
Both sides of an equation should have the same number of each type of atom
Electrical balance
Both sides of a reaction should have the same net charge
Q- When NaOH(aq) and MgCl2(aq) are mixed, _______(s) and NaCl(aq) are produced. Write balanced molecular, ionic & net ionic equations Mg(OH)2
Slide 4:
NaOH(aq) + MgCl2(aq) ? Mg(OH)2(s) + NaCl(aq)
Next, balance the equation First write the skeleton equation 2 2 Ionic equation:
2Na+(aq) + 2OH-(aq) + Mg2+(aq) + 2Cl-(aq) ? Mg(OH)2(s) + 2Na+(aq) + 2Cl-(aq) Net ionic equation:
2OH-(aq) + Mg2+(aq) ? Mg(OH)2(s)
Write balanced ionic and net ionic equations:
CuSO4(aq) + BaCl2(aq) ? CuCl2(aq) + BaSO4(s)
Fe(NO3)3(aq) + LiOH(aq) ? ______(aq) + Fe(OH)3(s)
Na3PO4(aq) + CaCl2(aq) ? _________(s) + NaCl(aq)
Na2S(aq) + AgC2H3O2(aq) ? ________(aq) + Ag2S(s) LiNO3 Ca3(PO4)2 NaC2H3O2
Slide 5:
Cu2+(aq) + SO42–(aq) + Ba2+(aq) + 2Cl–(aq) ? Cu2+(aq) + 2Cl–(aq) + BaSO4(s)
Net: SO42–(aq) + Ba2+(aq) ? BaSO4(s)
Fe3+(aq) + 3NO3–(aq) + 3Li+(aq) + 3OH–(aq) ? 3Li+(aq) + 3NO3–(aq) + Fe(OH)3(s)
Net: Fe3+(aq) + 3OH–(aq) ? Fe(OH)3(s)
2Na3PO4(aq) + 3CaCl2(aq)? Ca3(PO4)2(s)+ 6NaCl(aq)
6Na+(aq) + 2PO43–(aq) + 3Ca2+(aq) + 6Cl–(aq) ? Ca3(PO4)2(s)+ 6Na+(aq) + 6Cl–(aq)
Net: 2PO43–(aq) + 3Ca2+(aq) ? Ca3(PO4)2(s)
2Na+(aq) + S2–(aq) + 2Ag+(aq) + 2C2H3O2–(aq) ? 2Na+(aq) + 2C2H3O2–(aq) + Ag2S(s)
Net: S2–(aq) + 2Ag+(aq) ? Ag2S(s)