paper 2

• flame test for lithium

  crimson
• flame test for sodium

  yellow
• flame test for potassium

  lilac
• flame test for calcium

  orange-red
• flame test for chlorine


  green
• test for hydrogen gas

  hold a burning splint over an open test tube and a 'squeaky pop' shows hydrogen is present
• test for oxygen gas


  insert a glowing splint into a test tube and if it relights then oxygen is present
• test for carbon dioxide

  bubble gas through limewater and if the limewater turns cloudy then co2 is present
• test for chlorine 


  if damp litmus paper is put into a tube, the litmus paper is bleached and turns white in the presence of chlorine
• precipitate colour for copper 2+ ions

  blue
• precipitate colour for iron 2+ ions

  green
• precipitate colour for iron 3+ ions

  brown
• which ions form a white precipitate?

  calcium, magnesium and aluminium
• how can you differentiate between aluminium, calcium and magnesium ions?

  aluminium redissolves in excess sodium hydroxide solution
• how can you differentiate between calcium and magnesium ions?

  use a flame test (calcium has an orange flame while magnesium has no coloured flame)
• halides test?


  silver nitrate solution and nitric acid
• silver chloride precipitate colour

  white
• silver bromide precipitate colour


  cream
• silver iodide precipitate colour


  yellow
• sulfates test?


  dilute hcl and barium chloride