Tests for Ions Flashcards
What Ions do you test for with a flame test?
Ca(+) Cu(2+) Ba(2+) Li(+) K(+) Na(+)
How do you do a flame test?
Clean wire loop in HCl then rinse the water
Dip in sample solution
Hold loop over the flame
Flame test:
Ca(+)
Red
Flame test:
Cu(2+)
Blue / Green
Flame test:
Ba(2+)
Pale Green
Flame test:
Li(+)
Crimson
Flame test:
K(+)
Lilac
Flame test:
Na(+)
Yellow
What are Precipitation Reactions with Sodium Hydroxide?
Metal Chloride + Sodium Hydroxide –> Metal Hydroxide + Sodium Chloride
What ions can you test for with Sodium Hydroxide?
Fe(2+) Fe(3+) Cu(3+) Ca(2+) Mg(2+) Al(3+)
Precipitates with Sodium Hydroxide:
Fe(2+)
Green
Precipitates with Sodium Hydroxide:
Fe(3+)
Blue
Precipitates with Sodium Hydroxide:
Cu(3+)
Brown
Precipitates with Sodium Hydroxide:
Ca(2+)
White
Precipitates with Sodium Hydroxide:
Mg(2+)
White
Precipitates with Sodium Hydroxide:
Al(3+)
White but DISSOLVES in excess
Testing for Halide ions with displacement reactions
Add either Cl(-), Br(-), I(-) to a solution of KCl, KBr, KI
In KCl, KBr, KI precipitate is:
Cl(-)
KCl - Nonexistent KBr - Orange KI - Red/Brown
In KCl, KBr, KI precipitate is:
Br(-)
KCl - Orange KBr - Nonexistent KI - Red/Brown
In KCl, KBr, KI precipitate is:
I(-)
KCl - Red/Brown KBr - Red/Brown KI - Nonexistent
How does the Silver Nitrate test work?
Add Nitric acid HNO(3)
Add Silver Nitrate AgNO(3)
Add Ammonium NH(3)
What ions does the Silver Nitrate test for?
Cl(-), Br(-), I(-)
Cl (-)
Before Silver Nitrate:
After Silver Nitrate:
After Ammonium:
Before Silver Nitrate: Clear Colourless
After Silver Nitrate: White ppt.
After Ammonium: Ppt. dissolves
Br(-)
Before Silver Nitrate:
After Silver Nitrate:
After Ammonium:
Before Silver Nitrate: Clear Colourless
After Silver Nitrate: Pale Cream ppt.
After Ammonium: Ppt. dissolves in concentrate
Before Silver Nitrate:
After Silver Nitrate:
After Ammonium:
Before Silver Nitrate:Clear Colourless
After Silver Nitrate: Pale yellow ppt.
After Ammonium: Insoluble
How do you test for Sulfate ions?
Add few drops of HCl Add BaCl(2)
What is formed if Sulfate ions present?
White ppt.
How do you test for Carbonate ions?
Add dilute HCl
Collect gas
Run gas through limewater
If cloudy, Carbonate ions present