Overview
This lab focuses on identifying four unknown solutions (J, K, L, M) as calcium chloride, potassium chloride, sodium carbonate, or sodium phosphate using precipitation reactions and reactivity with nitric acid.
Identifying the Unknowns
- There are four unknowns, each one is either calcium chloride, potassium chloride, sodium carbonate, or sodium phosphate.
- The goal is to determine the identity of each unknown using chemical reactions.
Precipitation Reactions
- J mixed with K forms a fluffy white precipitate.
- J mixed with L forms a gelatinous precipitate.
- J mixed with M produces no precipitate.
- K mixed with L produces no precipitate.
- K mixed with M produces no precipitate.
- L mixed with M produces no precipitate.
Reactivity with Nitric Acid
- Adding 6M nitric acid to J: no observable reaction.
- Adding 6M nitric acid to K: bubbling and fizzing occurs.
- Adding 6M nitric acid to L: no observable reaction.
- Adding 6M nitric acid to M: no observable reaction.
Key Terms & Definitions
- Precipitate — a solid that forms from a solution during a chemical reaction.
- Precipitation Reaction — a reaction where two solutions combine to form an insoluble product.
- 6M Nitric Acid — a strong acid solution used to test reactivity of substances.
- Bubbling/Fizzing — evidence of gas formation, often from a reaction releasing CO₂.
Action Items / Next Steps
- Analyze results to deduce the identity of each unknown.
- Prepare a written lab report summarizing observations and conclusions.
- Review solubility rules and common precipitation reactions.