2.1.2 compounds, formulae and equations

• H3PO4 - phosphoric acid
• HNO3 - nitric acid
• H2SO4 - sulfuric acid
• NH3 - ammonia
• CH4 - methane
• sulfur S8
• ammonium - NH4+
• ion - charged particle which is formed by loss or gain of electron
• ide - element on its own
• ate - element + oxygen
• ite - element + one less oxygen than ate
• What is the solubility status of all compounds of the Ammonium ion (NH4+)?

  All are soluble
• Which cations are all soluble according to the solubility rules?

  Alkali Metals (Li+, Na+, K+, Rb+, Cs+)
• What is the solubility status of all Nitrates (NO3-)?

  All are soluble
• Which halides are generally soluble, and which exceptions exist?

  Chlorides, Bromides, Iodides are soluble except Ag+, Pb2+, Hg2+
• What is the solubility status of all Fluorides?

  All are insoluble except NH4+, Alkali metals, Be2+
• What is the solubility status of all Sulfates (SO42-)?

  All are soluble except Ag+, Pb2+, Hg2+, Ba2+, Sr2+, Ca2+
• What is the solubility status of Carbonates (CO32-), Sulfites (SO32-), and Phosphates (PO43-)?

  All are insoluble except NH4+ and Alkali metals
• What is the solubility status of Hydroxides (OH-)?

  All are insoluble except NH4+, Ba2+, Alkali metals
• What is the solubility status of Sulfides (S2-)?

  All are insoluble except NH4+, Alkali metals, Alkali earth metals
• What is the solubility status of Oxides (O2-)?

  All are insoluble except Ca2+, Ba2+, Alkali metals
• What happens to the soluble oxides when they react with water?

  They form hydroxides (e.g., NaOH, Ca(OH)2)
• What are the general solubility rules for cations and anions?

  • Ammonium ion (NH4+): All soluble
  • Alkali Metals (Li+, Na+, K+, Rb+, Cs+): All soluble
  • Nitrates (NO3-): All soluble
  • Chlorides, Bromides, Iodides: Soluble except Ag+, Pb2+, Hg2+
  • Fluorides: Insoluble except NH4+, Alkali metals, Be2+
  • Sulfates (SO42-): Soluble except Ag+, Pb2+, Hg2+, Ba2+, Sr2+, Ca2+
  • Carbonates, Sulfites, Phosphates: Insoluble except NH4+, Alkali metals
  • Hydroxides (OH-): Insoluble except NH4+, Ba2+, Alkali metals
  • Sulfides (S2-): Insoluble except NH4+, Alkali metals, Alkali earth metals
  • Oxides (O2-): Insoluble except Ca2+, Ba2+, Alkali metals; react with water to form hydroxides
• • take full equation
  • separate (aq) solutions into ions
  • cancel out spectator ions leaving the ionic equation