Chemistry

• Bromine water is orange in colour
• sulfur dioxide is acidic
• sulfur dioxide turns acidified potassium manganate from purple to colourless
• alkene reacts with bromine water and turns from orange to colourless
• sulfur dioxide is used as a bleach
• metal ion flame colour

  • lithium red
  • sodium yellow
  • potassium lilac
  • calcium orange-red
  • barium light-green
  • copper(ll) blue-green
• brass = copper + zinc

• bronze = copper + tin
• stainless steel = iron + carbon + nickle/chromium

• mild steel = iron + carbon
• Haber process:

  • N2(g) + 3H2(g) ⇌ 2NH3(g)
  • catalyst: iron
  • pressure: 200atm/20 000kPa
  • temperature: 450°C
  • nitrogen: air
  • hydrogen: methane
• Contact process:

  • 2SO2(g) + O2(g) ⇌ 2SO3(g)
  • catalyst: vanadium(V) oxide
  • pressure: 2 atm/200kPa
  • temperature: 450°C
  • sulfur dioxide: burning sulfur/roasting sulfur ores
  • oxygen: air
• saturated defines as a solution that can dissolve no more solute at a given temperature
• Isotope defines as the atom of the same element that has same proton number but different neutron number
• carbon dioxide is acidic
• carbon monoxide is neutral
• Methyl orange:

  Alkali - yellow, neutral - orange, acidic - red
• Forming soluble salt from insoluble reactants:

  filtration --> evaporation --> crystallisation