Slow Formation of a Chloro Complex of Chromium(III) Ion
Description A quantity of Hydrochloric acid is added to a sample of 0.01M Chromium (III) Nitrate. The mixture is heated and the solution changes color from a deep purple to a dark green in about 10 minutes of heating.
Cr(NO3)3(aq) + 3HCl(conc) + Δ → CrCl3(aq) + 3NO3-(aq) + 3H+(aq)
Source: UW Card Catalog
Year: N/A Vol: N/A Page: N/A
Keywords: Chromium, Ligands, Substitution, Lability, HCl, Ions
Rating: 
Hazard: Some
- Oxidizing Solids
- Skin irritation
- Eye irritation
- Skin sensitization
- Short-term (acute) aquatic hazard
- Long-term (chronic) aquatic hazard
- Corrosive to metals
- Skin corrosion hazard
- Serious eye damage
- Specific target organ toxicity-single exposure – respiratory system
Effectiveness: Average
- Results are observable without guidance
- Time to results is medium
- Good reliability
- Contrast between systems is noticeable
- Some connection from demo to course material
Difficulty: Medium
- Use of potential carcinogens
- Procedures with intermediate steps to results
- Reactions or demos at non-standard conditions
- Some timed manipulations
Safety Precautions:
- Eye protection required
- Gloves required
- Thermal gloves recommended
- Perform in a well-ventilated area
- Use UL-approved three-prong plug and outlet
- Avoid inhalation or exposure to mists, droplets, or vapors
- Prevent release of reagents to the environment
- Absorbent materials on hand
- Sodium bicarbonate on hand
Class: Equilibrium, Transition Metals and Coordination Compounds
Division: Inorganic Compounds, General Chemistry
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