| 1. | Safety |
| 2. |
Objectives/Overview |
| 3. |
Procedures |
|
4. |
Observations |
| 5. | |
| 6. | |
| 7. | Conclusions |
| 8. | Grading Scale |
| 9. | Review Prelab Questions |
|
10. |
Review Postlab Questions |
Experiment
21
Qualitative
Analysis of a Salt Unknown
POST-LABORATORY QUESTIONS
1. A salt unknown containing one cation and one anion is a white solid that dissolves in water to form a colorless solution.
ion(s) possibly present:ion(s) absent:
2. Addition of NH3 and NH4Cl to a solution of the salt gives no precipitate. Addition of (NH4)2CO3 gives a white precipitate.
ion(s) present:
ion(s) absent:
ion(s) inconclusive:
3. The white precipitate from 4 dissolves in acetic acid. Addition of K2CrO4 gives a yellow precipitate which does not dissolve upon heating.
ion(s) present:
ion(s) absent:
ion(s) inconclusive:
4. When BaCl2 is added to a solution of the unknown salt, no precipitate is formed.
ion(s) present:
ion(s) absent:
ion(s) inconclusive:
5. When AgNO3 is added to a solution of the unknown salt, no precipitate is formed.
ion(s) present:
ion(s) absent:
ion(s) inconclusive:
6. The addition of 3M H2SO4 caused rapid bubbling and the formation of a brown gas near the mouth of the test tube. No further tests were done.
ion(s) present:
ion(s) absent:
ion(s) inconclusive:
7. What is the formula for the salt?
8. Although you have enough evidence to identify the salt, what additional tests should be performed to confirm your hypotheses?
