Chemical tests

• test for hydrogen

  lit splint will ignite with a squeaky pop
• test for oxygen

  glowing splint will relight
• test for carbon dioxide

  limewater turns cloudy
• test for ammonia

  damp red litmus turns blue
• test for chlorine

  damp blue litmus turns red then bleaches white
• flame test

  nichrome wire dipped in HCl then salt or wooden splint soaked in solution

  in roaring blue flame
• lithium flame

  red
• calcium flame

  orange red
• potassium flame

  lilac
• copper flame

  blue
• sodium flame

  yellow
• testing for cations

  add sodium hydroxide

  NH4+ heated and tested with litmus paper

  CU2+ = blue precipitate

  Fe2+ = green grey precipitate

  Fe3+ = orange brown precipitate
• testing for carbonates

  add HCl and bubble through limewater
• testing for halides

  add nitric acid then silver nitrate

  Cl- = white precipitate

  Br- = cream precipitate

  I- = yellow precipitate
• testing for sulfates

  add HCl

  add barium chloride

  white precipitate forms
• test for presence of water

  anhydrous copper (II) sulfate turns white to blue
• test for pure water

  boils at exactly 100 degrees C