Activity #3 Analysis of Group V Cations

Question 1

What are the GV Cations

Answer 1

Ammonium, Potassium and Sodium

Question 2

Properties of GV Cations

Answer 2

• soluble in water in any form
• no simple precipitating agent can be used to
  separate them
• ammonia is always use as a reagent throughout the cation analysis there is always a presence of it in the solution
• necessary that test for ammonium will be done in the first step of all cation
  analysis

Question 3

Confirmation for Sodium ion

Answer 3

• FLAME TEST: Color Intense yellow

Question 4

Confirmation for Potassium ion

Answer 4

• FLAME TEST: Lilac (in Cobalt glass)
  Pink (w/o cobalt glass)

Question 5

Confirmation for Ammonium ion:

Answer 5

• strong base (either NaOH or KOH) to upset the equilibrium forming ammonia gas
• NH4
  + + OH- . NH3 + H2O
  +

Question 6

Confirmatory test for Ammonium gas

Answer 6

• formation of pungent odor or testing with litmus paper (red becomes blue)