Electrolytes

Purpose

Illustrate that ions are necessary to conduct electricity.

Procedure

1. Introduction:
   • Explain the function of the conductivity probe verbally.
   • Present various solutions to the class.
2. Prediction:
   • Ask students to predict the conductivity of tap water.
   • Note: Tap water may not be conductive enough; consider spiking the beaker with salt if needed.
3. Testing Solutions:
   • Conductivity tests for the following:
     • Distilled water
     • Tap water
     • Sugar water
     • Salt water
4. Dilutions:
   • Use 50:50 dilutions of the following:
     • HCl
     • H₂SO₄
     • HNO₃
     • CH₃COOH (acetic acid)

Alternate Presentation

• Gatorade as Example:
  • Discuss Gatorade’s claim of containing electrolytes.
  • Test Gatorade’s conductivity to verify this claim.

5. Investigate Conducting Components:
   • Start with distilled water.
   • Test sugar (High Fructose Corn Syrup).
   • Add more sugar to see if increased concentration affects conductivity.
   • Test salt and potassium phosphate.

Conductance Measurement

• Use Vernier conductivity meter to show conductance differences in:
  • 0.1 M NaCl
  • 0.2 M NaCl
  • 0.5 M NaCl

Additional Solutions for Testing

• Lead (II) nitrate
• KI (Potassium Iodide)
• Gatorade
• Distilled water (DI water)
• Diluted CH₃COOH
• Glucose