ALL TESTS

• What colour ppt does Al3+ make when it reacts with NaOH?

  white
• What colour ppt does Mg2+ make when it reacts with NaOH?

  white
• What colour ppt does Ca2+ make when it reacts with NaOH?

  white
• What colour ppt does Fe2+ make when it reacts with NaOH?

  green
• What colour ppt does Fe3+ make when it reacts with NaOH?

  brown
• What colour ppt does Cu2+ make when it reacts with NaOH?

  blue
• Fe3+ ions form brown ppts and are yellow in solutions
• What is the test for Sulfate ions?

  • add dilute HCL to remove any carbonates
  • add BaCl2
  • if present, BaSO4 forms, which is a white ppt
• Test for carbonates?

  • add dilute HCl
  • effervescence should occur
  • bubble gas produced through limewater to confirm the presence of CO2
• Test for Ammonium ions (NH4+)?

  • add NaOH
  • warm gently
  • test the gas produced with damp litmus paper, turns blue