Chemistry

• Solute

  Substances that can be dissolved in other substances
• Solvent

  Substance that can dissolve other substance
• Saturated solution

  A solution that can dissolve no more solute at a given temperature
• Equilibrium

  Equal rate of reaction

  Constant concentration
• Electroplating

  Anode: pure metal - mass decrease

  Cathode: object - mass increase

  Electrolyte: soluble salt of pure metal
• Extraction of iron

  Raw materials: hematite, coke, limestone, hot air

  Waste gases: nitrogen oxide & carbon dioxide
• Extraction of iron

  
  

  Coke burns

  • C + O -> CO2

  Carbon dioxide reduced

  • CO2 + C -> 2CO

  Carbon monoxide reduces iron oxide

  • Fe2O3 + 3CO -> 2Fe (III) + 3CO2

  Limestone thermally decomposes

  • CaCO3 -> CaO + CO2

  Calcium oxide neutralised silicon dioxide & form slag

  • CaO + SIO2 -> CaSiO3
• Extraction of Aluminium

  Electrolysis: bauxite

  More reactive than carbon so can't be reduced by it
• Extraction of Electrolysis

  Molten cryolite: lower melting point & increased conductivity

  Graphite cathode:

  • Al 3+ + 3e- -> Al

  Anode:

  • 2O 2- -> O2 + 4e-

  Overall:

  • 2Al2O3 -> 4Al + 3O2
• Haber process

  Pumps H2 & N2

  Gases compressed at 200 atm

  Pump gas at 450 C

  N2 + 3H2 -> 2NH3
• Haber Process

  Exothermic

  Temperature: 450 C

  Pressure: 200 atm

  Catalyst: Iron

  Produced: NH3, H2, N2
• Contact Process

  Burning sulfur

  • S + O2 -> SO2

  Oxidise sulfur dioxide + V2O5

  • 2SO2 + O2 -> 2SO3

  Adds HCL

  • SO3 + H2SO4 -> H2S2O7 (oleum: safer to transport)

  Adds water

  • H2SO4 + H2O -> 2H2SO4
• Contact process


  Temperature: 450 C

  Pressure: 2 atm

  Catalyst: Vanadium (V) Oxide
• Homologous series

  Same: general formula, chemical properties, functional group

  Different: molecule formula, physical properties
• Fermentation

  Glucose -> Ethanol + Carbon Dioxide

  Yeast

  Less than 60 C

  Safe but also slow and low yield
• Addition

  Alkene + steam -> Alcohol

  60 atm, 300 C

  Fast and more yield but toxic
• Oxidation

  Oxidised Alcohol -> Carboxylic acid
• Esterification

  Carboxylic acid + Alcohol -> Ester + Water
• Terylene:

  Polyester 

  Monomers joined together by ester links
• Proteins

  Condensation polymers

  Amino acid joined together by amide links