chem reactions

Synthesis

• A + X → AX

  • A and X can be elements or simple compounds

  • AX is a compound

• element + oxygen → oxide of element

• metals + sulfur → sulfides

• nonmetals + oxygen → oxides

• oxides of active metals + water → metal hydroxides

Decomposition

• AX → A + X

• electrolysis - decomposition of water using electricity

• exceptions

  • metal carbonate → metal oxide + carbon dioxide

  • metal hydroxide → metal oxide + water vapor

  • metal chlorate → metal chloride + oxygen gas

Single Replacement

• A + BX → AX + B where A+B are metals

• Y + BX → BY + X where Y+X are nonmetals

• reactivity

  • group 1A increases ↓

  • halogens decreases ↓

• most active metals + water → metal hydroxide + hydrogen gas

• less active metals + steam → metal oxide + hydrogen gas

• more reactive metals + some acids

Double Displacement

• AX + BY → AY + BX

• one compound produced:

  • precipitate

  • insoluble gas

  • molecular compound (usually water)

• other compound usually aqueous

Combustion

• Cx + Hy + O2 → CO2 + H2O

Identification

1. only one reactant? → decomposition

2. reactants two elements / simple compounds? → synthesis

3. reactants oxygen + hydrocarbon? → combustion

4. reactants element + compound (not hydrocarbon) → single

5. reactants two compounds composed of ions? → double