Effect of Ionic Strength on Ion Dissociation
Description: The effect of ionic strength on dissociation is tested using an iron (III) thiocyanate complex. Mixing a solution of iron (III) and KSCN produces a pale red solution. Adding potassium nitrate to the solution causes the color to fade.
Source: Harris, Daniel C. Quanitative Chemical Analysis 2nd ed.
Year: 1999 Vol: N/A Page: 177
Keywords: Iron (III) Thiocyanate complex, Potassium Nitrate, Ionic strength, Dissociation
Rating: 
Hazard: Medium
- Acute toxicity hazard- oral, inhalation, dermal
- Corrosive to metals
- Serious eye damage
- Oxidizing liquids
- Aquatic toxicity hazard
- Skin corrosion hazard
Effectiveness: Good
- Good connection from demo to course material
- Results are clearly observable without guidance
- Clear contrast between systems behavior
- Low failure rate
- Time to results is low
Difficulty: Medium
- Some concerted or timed manipulations
- Use of toxic substances
- Some physical manipulations
Safety Precautions:
- Eye protection required
- Gloves required
- Absorbent materials on hand
- Avoid exposure to mists, dusts, or vapors
- Prevent release of reagents to the environment
- Sodium bicarbonate on hand
Class: Dissociation, Solubility, Equilibrium
Division: Analytical Chemistry, General Chemistry
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