1 / 9

Chapter 7 Electrochemistry

Chapter 7 Electrochemistry. § 7.3 Applications of Conductivity Measurement. Main contents: Monitoring the purity of water Measurement of ionizability Determine solubility product and ionic product Conductometric titration. Silicon wafer. 1. Monitor the purity of water. Group works:

oakley
Download Presentation

Chapter 7 Electrochemistry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 7 Electrochemistry §7.3 Applications of Conductivity Measurement • Main contents: • Monitoring the purity of water • Measurement of ionizability • Determine solubility product and ionic product • Conductometric titration

  2. Silicon wafer 1. Monitor the purity of water Group works: Calculate the conductivity of pure water. at 25 oC, Kw = 10-14, [H+] = [OH] = 10-7 mol·dm-3 Fabrication of VLSI

  3. In-situ monitoring of the cleaning process : H2O2/H2SO4 DW rinse  dilute HF  SC-1 cleaning  DW rinse  hot DW rinse  DW rinse  SC-2 cleaning  DW rinse  dilute HF  DW rinse. DW - deionized water, SC-1: H2O2/NH3; SC – standard cleaning,SC-2: H2O2/HCl.

  4. 2. Measure the ionizability and dissociation constant c+ =c At infinite dilution Arrhenius suggested that the degree of dissociation of an electrolyte can be calculated using molar conductivity.

  5. mc Ostwald showed how one can measure the dissociation constant of an acid. Ostwald dilution law The equation can be rearranged to Linearization

  6. 3. Determine solubility and solubility products Example: The conductivity of a saturated AgCl solution is 1.86  10-4 S·m-1, while that for water is 6.0  10-6 S·m-1. Molar conductivity of AgCl is 0.01372 S·mol-1·m2. Calculate the solubility product for AgCl.

  7. 5. Determine ion product of water Water can be taken as a dilute solution of a strong electrolyte CH+ = COH- = Kw1/2 The specific conductance of highly purified water is 5.478 10-6 S·m-1. Calculate the concentration of hydrogen ion in water.

  8. A C / S·m-1 C’ B A’ B’ endpoint V / ml 6. Conductometric titration The conductance variation of a solution during titration can serve as a useful method to follow the course of the reaction. Ionic mobility of ions: Na+ + OH- + (HCl) = 5.19 20.52 Na+ + Cl- +(H+ + Cl-) 5.19 7.91 36.30 Precipitation reactions, neutralization reactions, and coordination reactions

More Related