Table 3: Test observations and results with known anions
|
Procedure |
Anion |
Actions |
Observations |
|
1. Ba(NO3)2 test for PO43- and SO42- ions |
PO43- |
Added Ba(NO3)2
|
-turned white -precipitated |
|
Added 6 M HNO3 |
-white precipitate separated and sat on bottom of tube |
||
|
SO42- |
Added Ba(NO3)2 |
- precipitate turned white |
|
|
Added 6 M HNO3 |
- precipitate separated from solution to bottom |
||
|
Cl- |
Added Ba(NO3)2 |
- did not precipitate |
|
|
|
|
||
|
NO3- |
Added Ba(NO3)2 |
-precipitated partially (some white) |
|
|
Added 6 M HNO3 |
|
||
|
AgNO3 test for Cl- ions and PO43- ions |
PO43- |
Added 2 drops AgNO3 |
-clear - no precipitate |
|
SO42- |
Added 2 drops AgNO3 |
- no precipitate - clear like water |
|
|
Cl- |
Added NH3 4 drops |
- precipitate dissolved |
|
|
NO3- |
Added AgNO3 |
- no precipitate |
|
|
Brown ring test for NO3- |
NO3- |
Added H2SO4 (concentrated) NaNO3 |
-unknown 1 had nitrate in it, brown ring present |
Table 4: Analysis of unknown solution
|
Step |
Action |
Observations |
Anion Present |
|
1 |
Added Ba(NO3)2 – 2 drops to unknown 1 |
No precipitate formed |
Cl- no precipitate formed |
|
Added Ba(NO3)2 – 2 drops to unknown 2 |
Somewhat murky colored |
NO3- nitrate |
|
|
2 |
Added 2 drops of AgNO3 to supernatant 1 |
Precipitate formed |
Chloride Cl- |
|
3 |
Added NaNO3 |
Test tube with unknown 1 had nitrate in, brown ring present |
________________________ |
|
Nitrate test (ions) |
Unknown 2 had no brown ring |
Nitrate present |