M

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