User:Melissa Novy/Notebook/CHEM-572/2013/01/29

Objectives

• Calculate mass of AgNO₃ necessary to achieve 95% CEC with Laponite (LMT).
• Begin ion exchange reaction with AgNO₃ and LMT.

Calculations

  MW AgNO3: 169.87 g/mol
  MW Ag+: 107.86 g/mol
  CEC Laponite: 55 meqv/100 g
  0.3 g LMT × (55 meqv/100 g LMT) × (1 mol Ag+/1000 meqv) × (107.86 g Ag+/1 mol Ag+) × (1 mol AgNO3/1 mol Ag+) × (169.87 g AgNO3/1 mol AgNO3) × 95% = 2.87200 g AgNO3

Laponite-Ag⁺ Ion Exchange

• Protocol
  1. Place 0.3 g Laponite and 2.87200 g AgNO₃ in a clean, dry 50-mL Erlenmeyer flask with a stir bar.
  2. Pour in 10 mL of (50:50) H₂O:EtOH, i.e. 5 mL of H₂O and 5 mL of EtOH.
  3. Cover and cap the flask with aluminum foil.
  4. Stir at room temperature for 24 h.

• Theoretical mass Laponite: 0.3 g
  • Actual mass Laponite: 0.30038 g

• Theoretical mass AgNO₃: 2.87200 g
  • Actual mass AgNO₃: 2.87897 g

• Observations: The solution became opaque and white in color after all components were added.