Hazards:
Avoid contact with silver compounds as they will stain skin and clothing.
Chemicals and Solutions:
0.1 M Na2CO3 ( 1 mL)
0.1 M AgNO3 (10 mL)
0.1 M NaOH (10 mL)
0.1 M NaCl (30mL)
5 M NH3 (35 mL)
0.1 M NaBr (10 mL)
0.1 M Na2S2O3 (50 mL)
0.1 M KI (10 mL)
Materials:
600 mL beaker
200 mL water
Magnetic stirrer and bar
Procedure:
Add 200 mL and a stirring bar to the 600 mL beaker and begin stirring.
Starting with 1 mL of sodium carbonate add the solutions consecutively to the water in the order listed in the materials section. Precipitates will form and disappear.
Hint:
Discussion:
Precipitate |
Color |
Ksp |
Moles/L |
|
Ag2CO3 |
white |
8.1 x 10-12 |
1.2 x 10-4 |
most soluble |
AgOH |
brown |
6.8 x 10-9 |
8.2 x 10-5 |
|
AgCl |
white |
1.8 x 10-10 |
1.3 x 10-5 |
|
AgBr |
yellow |
7.7 x 10-13 |
8.8 x 10-7 |
|
AgI |
yellow |
8.3 x 10-16 |
1.2 x 10-8 |
least soluble |
2Ag+ + CO32- ---> AgCO3 (white solid)
Ag2CO3 + 2OH- ---> 2AgOH + CO32- (brown solid)
AgOH + Cl- ---> AgCl + OH- (white solid)
AgCl + 2NH3 ----> Ag(NH3)2+ + Cl- (colorless)
Ag(NH3)2 + + Br- ---> AgBr + 2NH3 (yellow solid)
AgBr + 2S2O32- ---> Ag(S2O3)23- + Br-(colorless)
Ag(S2O3)23- + I- ---> AgI + 2S2O32-(yellow)
Hazards: Avoid contact with silver compounds, they will stain skin and clothing
To schedule a demonstration, please send an email to the demonstration lab.
Contact:
Eric Camp
Lecture Demonstration Technician
Bagley Hall 171
(206) 543-1606