ION TESTS

• TEST FOR SO4 IONS?

  1. Acidify with dilute HCl
  2. Add BaCl
  3. White precipitate (BaSO4) produced
• TEST FOR CO3 IONS?

  1. Add dilute HCl
  2. Effervescence
  3. Bubble through limewater
  4. Turns cloudy
• TEST FOR OH- IONS?

  1. Damp red litmus paper
  2. Turns blue
• TEST FOR HALIDE IONS?

  1. Acidify with dilute HCl
  2. Add AgNO3
  3. Add dilute then concentrated NH3

  RESULTS

  Cl-: white precipitate, dissolves in dilute NH3

  Br-: cream precipitate, dissolves in concentrated NH3

  I-: pale yellow precipitate, insoluble in concentrated NH3
• TEST FOR G2 METALS?

  TEST 1: Add NaOH dropwise until in excess

  • Mg2+: SWP, WP
  • Ca2+: SWP, SWP
  • Sr2+: SWP, SWP
  • Ba2+: NVC, NVC

  TEST 2: Add dilute H2SO4 dropwise until in excess

  • Mg2+: SWP, CS
  • Ca2+: SWP, SWP
  • Sr2+: WP, WP
  • Ba2+: WP, WP

  TEST 3: Flame tests

  • Ca2+: brick red
  • Sr2+: red
  • Ba2+: green
• TEST FOR SOLID CHLORIDE?

  1. Add concentrated H2SO4
  2. Test gas with damp blue litmus paper
  3. Effervescence
  4. Litmus paper turns red
• TEST FOR SOLID BROMIDE?

  1. Add concentrated H2SO4
  2. Test gas with filter paper dipped in acidified potassium dichromate solution
  3. Effervescence
  4. Brown gas produced
  5. Solution turns red/ brown
• TEST FOR SOLID IODIDE?

  1. Add concentrated H2SO4
  2. Test gas produced with filter paper dipped in lead nitrate solution
  3. Brown gas produced
  4. Solution turns red/ brown
  5. Paper turns black
• MOLECULE SHAPES AND ANGLES?

  L (180)

  Tpl (120) B (119)

  T (109.5) Tpy (107) B (104.5)

  Tb (120/90) Tb (120/90) Ts (89) L (180)

  O (90) Spy (89) Spl (90) Ts (89) L (180)