Inorganic Test-Tube Reactions

SO₄^2-

• Add HNO₃ and then Ba(NO₃)₂

• White ppt produced

• Ba²⁺ + SO₄^2- → BaSO₄

Note: HNO₃ is added to react and destroy any other ions

CO₃^-

• Add HCl

• Test any gas produced by passing it through limewater

• Limewater should go cloudy

• 2H⁺ + CO₃^2- → CO₂ + H₂O

Cl^-

• Add HNO₃

• Add AgNO₃

• Test any ppt formed with dilute and conc NH₃

  • Ag⁺ + Cl^- → AgCl (white ppt)

  • AgCl → Ag(NH₃)₂⁺ + Cl^-

  • soluble in dilute NH₃

Br^-

• Add HNO₃

• Add AgNO₃

• Test any ppt formed with dilute and conc NH₃

  • Ag⁺ + Br^- → AgBr (cream ppt)

  • AgBr → Ag(NH₃)₂⁺ + Br^-

  • soluble in conc NH₃

I^-

• Add HNO₃

• Add AgNO₃

• Test any ppt formed with dilute and conc NH₃

  • Ag⁺ + Br^- → AgBr (yellow ppt)

  • insoluble in NH₃