5 categories of chem. rxn.
1. Synthesis
2. Decomposition
3. Single replacement
4. Double replacement
5. Combustion
1. Synthesis
Two or more substances put together
A + B ABGeneral
Specific Example
2Na + Cl2 2NaCl
2. Decomposition
Compound breaks down into 2 (or more) substances
AB A + BGeneral
Specific Example
H2O2 H2O + O22 2
• Hydrogen peroxide decomposes into water & oxygen gas
3. Single-replacement
One element replaces another in a compound
AB + C CB + AGeneral
MgCl2 + 2 Li 2LiCl + Mg
• Li takes place of Mg
3CuSO4+2Al Al2(SO4)3+ 3Cu
• Al takes the place of Cu
Specific Example
4. Double replacement
The positive portions ( + ions) are exchanged
General
AX + BY AY + BX
Specific Example
AgNO3+NaBr AgBr +NaNO3
• Ag+ & Na+ exchange places
5. CombustionSubstance combines w/ oxygen rapidly - forms one or more oxides
Substance A + O2
Substance oxide + energy
• releases energy
Specific Example
2 C2H2 + 5 O2 4 CO2 + 2 H2O + energy
• Acteylene combines w/ oxygen & produces carbon dioxide & water & releases energy
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