acid alkali

• anhydrous copper sulfate


  • to test presence of water
  • turn grey to blue
• indicators

  Universal indicators - acid & alkaline

  Litmus (purple blue/red) - acid & alkaline

  methyl orange (orange) - acid

  phenolphthalein (colourless) - alkaline
• base

  • neutralise acid to form salt
• test for O2

  relight a glowing splint

  2Mg + O2 -> 2MgO
• test for CO2

  Limewater turn milky

  CO2 + H2O -> H2CO3
• Test for H2


  Combustion (pop sound)

  2Mg + H2 -> 2MgH
• Test Cl2

  turn red

  Cl2 + H2O -> HCL + HOCL
• test NH3

  turn blue

  NH3 + H2O <-> NH4OH