Symbols, Formula and Equations (1.5)

• What does a chemical formula provide for a substance?

  Name for the substance
• What does a chemical equation describe?

  How substances change during a reaction
• What do the symbols (g), (l), (s), and (aq) represent in equations?

  States of matter: gas, liquid, solid, aqueous
• What type of compounds are ionic compounds?

  Compounds of metal and non-metal
• How do metals achieve a full outer shell in ionic compounds?

  By losing electrons to form positive ions
• How do non-metals achieve a full outer shell in ionic compounds?

  By gaining electrons to form negative ions
• What is the process for writing a chemical formula for ionic compounds?

  Write down ions, swap numbers, write ratio
• What is the chemical formula for sodium oxide?

  2NaO
• What happens to the name of a non-metal when it forms a compound with a metal?

  It changes to end in -ide
• What does a compound ending in -ate indicate?

  Oxygen is present in the compound
• What are molecular ions?

  Charged particles with more than one element
• How many covalent bonds does carbon form?

  Four covalent bonds
• What prefix indicates one atom in a covalent compound?

  Mono-
• What are the formulas for common substances?

  • Water: H₂O
  • Hydrochloric acid: HCl
  • Nitric acid: HNO₃
  • Sulfuric acid: H₂SO₄
  • Methanoic acid: HCOOH
  • Ethanoic acid: CH₃COOH
  • Propanoic acid: C₂H₅COOH
  • Butanoic acid: C₃H₇COOH
  • Methanol: CH₃OH
  • Ethanol: C₂H₅OH
  • Methane: CH₄
  • Ammonia: NH₃
  • Carbon dioxide: CO₂
  • Sulfur dioxide: SO₂
  • Sulfur trioxide: SO₃
  • Nitrogen dioxide: NO₂
  • Carbon monoxide: CO
  • Oxygen: O₂
  • Hydrogen: H₂
• What are the general types of chemical reactions represented by word equations?

  1. Metal + Acid → Salt + Hydrogen
  2. Base + Acid → Salt + Water
  3. Acid + Carbonate → Salt + Water + Carbon dioxide
  4. Acid + Ammonia → Ammonium Salt
  5. Metal + Oxygen → Metal Oxide
  6. Metal + Water → Metal Hydroxide + Hydrogen
  7. Metal + Steam → Metal Oxide + Hydrogen
  8. Metal + Halogen → Metal Halide
• What do ionic equations show?

  Only the ions involved in a reaction
• What is the ionic equation for neutralization?

  H⁺(aq) + OH⁻(aq) → H₂O(l)
• What is the ionic equation for precipitation?

  Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
• What is the ionic equation for displacement?

  Cu(s) + 2Ag⁺(aq) → 2Ag(s) + Cu²⁺(s)
• What do half equations show?

  Half of the reaction involving electrons
• How do you balance a half equation?

  Balance atoms and charges using electrons
• What is the half equation for magnesium reacting with electrons?

  Mg²⁺ + 2e⁻ → Mg