3. Practice: Chemical reactions are generally classified into five groups, defined below. Balance each equation, using the Gizmo for help.
Combination (or synthesis) - two or more elements combine to form a compound.
Na + O2 → Na2O
2Na + O2 → Na202
La2O3 + H2O → La(OH)3
.
N2O5 + H2O → HNO3
Decomposition - a compound breaks down into elements and/or simpler compounds.
KNO3 → KNO2 + O2
NaN3 → Na + N2
.
NH4NO3 → N2O + H2O
Combustion - a fuel reacts with oxygen to release carbon dioxide, water, and heat.
CH4 + O2 → CO2 + H2O
C3H8 + O2 → CO2 + H2O
C6H12O6 + O2 → CO2 + H2O
Single replacement - an element replaces another element in a compound.
.
KCL + F2 → KF + Cl2
.
Mg + HCl → MgCl2 + H2
Cu + AgNO3 → Cu(NO3)2 + Ag