paper 2

• Calculating volume of carbon dioxide produced

  1. Balance symbol equation

  2. Use mass, molar mass, and mole conversion to volume
• Titration calculations


  1. Use balanced symbol equation

  2. Calculate moles from concentration and volume

  3. Calculate concentration from moles and volume
• Electrolysis


  Breaking apart a substance using electricity, requires a molten ionic compound
• Cathode


  • Negative electrode, attracts cations (positive ions)
• Anode


  • Positive electrode, attracts anions (negative ions)
• Determining ions discharged in electrolysis

  1. At anode: halogens win, then oxygen

  2. At cathode: least reactive element wins
• Electrolysis of aqueous sodium chloride

  • Hydrogen gas formed at cathode
  • Chlorine gas formed at anode
• Electrolysis of copper(II) sulfate solution

  • Copper metal formed at cathode
  • Oxygen gas formed at anode
• Exothermic reaction


  Releases heat energy, products have lower energy than reactants
• Endothermic reaction


  Absorbs heat energy, products have higher energy than reactants
• Chemical equilibrium


  • Forward and reverse reactions occur at same rate, concentrations remain constant
• Altering position of equilibrium

  1. Decrease temperature to favour exothermic forward reaction

  2. Increase pressure to favour reaction with fewer moles of gas
• Catalyst


  Increases rate of both forward and reverse reactions equally, does not affect yield
• Alcohols


  Organic compounds with -OH functional group
• Carboxylic acids


  Organic compounds with -COOH functional group
• Ester formation


  Alcohol reacts with carboxylic acid in condensation reaction, producing ester and water
• Polyesters


  Polymers formed from dicarboxylic acids and dialcohols
• Naming esters: first part from alcohol, second part from carboxylic acid
• Ester


  Formed by the reaction of an alcohol and a carboxylic acid, with the loss of water
• Making Esters


  1. Need a sulfuric acid catalyst

  2. Reversible reaction

  3. Condensation reaction (loss of water)
• Reactants to make Esters

  • Alcohol
  • Carboxylic acid
• Products of Ester formation

  • Ester
  • Water
• Functional groups


  • Alcohol
  • Carboxylic acid
  • Ester
• Naming Esters


  Start of name from alcohol, end from carboxylic acid
• Ester formation


  • Methanol + Ethanoic acid → Methyl ethanoate + water
• Carboxylic acids


  React with metals to form a salt + hydrogen
• Carboxylic acid + metal carbonate


  Produce salt + water + carbon dioxide
• Oxidation of alcohols


  1. Microbial oxidation

  2. Complete combustion

  3. Heating with potassium dichromate and sulfuric acid
• Electrolysis


  Electrolyte must be molten or in aqueous solution for ions to move freely

  At cathode (negative electrode): positive ions (cations) attracted and reduced

  At anode (positive electrode): negative ions (anions) attracted and oxidised
• Making a soluble salt from insoluble reactants


  Add reactants, stir, filter to remove excess insoluble reactant, heat to evaporate water, allow to cool and dry
• Making an insoluble salt from soluble reactants

  Mix reactants, filter to remove insoluble salt, wash with water to remove excess reactants, dry
• Making a soluble salt from acid and alkali

  Titrate to find exact volumes, mix, heat to evaporate, cool, dry
• Exothermic reaction (negative ΔH)


  Decrease temperature to increase yield of products
• Reaction with fewer moles of gas on product side

  Increase pressure to increase yield of products