Guy Lusaac's Law

• Gay-Lussac lived


  1778-1850
• In 1802 he went up to 23,000 feet in a balloon – a record for 50 years
• Wanted to investigate the composition of the atmosphere as a function of altitude
• Gay-Lussac examined relationship


  Between pressure and temperature at constant volume and moles
• If temperature increases


  The gas molecules will move faster, colliding with the walls more frequently and more energetically
• Pressure results from collisions between gas molecules and walls of container


  If temperature increases, pressure increases
• Convert the temperature from Celsius scale into Kelvin scale (i.e. T(K) = T(C) + 273)
• Gay-Lussac's Law
• Chemical Equation


  A chemical formula that represents a chemical reaction
• Components of a chemical equation

  • Reactant(s)
  • Product(s)
• O


  O
• Combination (or Synthesis) Reaction


  • Two or more reactants combine to form a single product
• Decomposition Reaction


  • A single reactant breaks down to form two or more products
• Single Replacement (Substitution) Reaction


  • One element reacts by replacing another element in a compound
• Double Replacement (Metathesis) Reaction


  • Cations (positive ions) and anions (negative ions) of different compounds switch places, forming two entirely different compounds
• Combustion (Burning) Reaction


  • Oxygen combines with a hydrocarbon (compound containing hydrogen and carbon) to form water and carbon dioxide
• Law of Conservation of Mass


  Matter is conserved in a chemical reaction. The total mass of the reactants is equal to the total mass of the products. No new atoms are created or destroyed, there is only grouping or regrouping (rearrangement) of atoms.
• Antoine Lavoisier showed that a closed system must be used when studying chemical reactions. When chemicals are reacted in a closed container, you can show that the mass before and after the reaction is the same.
• Physical Change


  1. Sodium hydroxide (NaOH) dissolves in water (H2O)

  2. Water [H2O(l)] is heated and changed to steam [H2O(g)]
• Chemical Change


  1. Hydrochloric acid [HCl(aq)] reacts with potassium hydroxide to produce potassium chloride (KCl) salt, water (H2O), and heat

  2. Potassium chlorate (KClO3) decomposes to potassium chloride (KCl) and oxygen gas (O2)
• A pellet of sodium (Na) is sliced in two.