1. 每日一句 表面无功利、无目的的艺术，之所以受到人们的普 遍重视，是因为其隐含着提高人类想象力和创造力的潜 在功能。 陈炎，《文明呓语》，山东教育出版社， 140

2. Kohlrausch 5. Kohlrausch’s empirical formula 0.01 0.02 0.03 0.04 0.00 0.050.10 0.150.20  m / S·mol -1 ·m 2 HCl H 2 SO 4 KCl Na 2 SO 4 HAc Extroplate

3. Na 2 SO 4, HCOOH?

4. ionsr / nm 10 2 ionsr / nm 10 2 H+H+  3.4982OH¯  1.98 Li + 0.680.387F¯1.230.554 Na + 0.980.501Cl¯1.810.763 K+K+ 1.370.735Br¯1.960.784 Mg 2+ 0.741.061CO 3 2   1.66 Ca 2+ 1.041.190C2O42C2O42  1.48 Sr 2+ 1.041.189Fe(CN) 6 3   3.030 Al 3+ 0.571.89Fe(CN) 6 4   4.420 Fe 3+ 0.672.04 La 3+ 1.042.09 1) Nature of ions Charge; Radius; charge character; transfer mechanism 7.2.7 Influential factors for

5. G   UUU ttt MacroscopicMicroscopic Dynamic Summary

6. § 7.3 Applications of Conductivity Measurement

7. 1. Monitor the purity of water Group works: Calculate the conductivity of pure water. at 25 o C, K w = 10 -14, [H + ] = [OH  ] = 10 -7 mol·dm -3 waterTap water Distilled water Deionized water Pure water  /S·m -1 1  10 -2 ~1  10 -3 <1  10 -4 5.478  10 -6 Fabrication of VLSI Silicon wafer

8. In-situ monitoring of the cleaning process : H 2 O 2 /H 2 SO 4  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: H 2 O 2 /NH 3 ; SC – standard cleaning, SC-2: H 2 O 2 /HCl.

9. 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.

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

11. 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 ·m 2. Calculate the solubility product for AgCl.

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

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

15. Group discussion 1 ） For NaOH aqueous solution and alcohol solution with the same concentration, which shows higher conductivity. Why? 2) Which ionic mobility is higher, Na + or Mg 2+ ? which diffusion coefficient is higher, Na + or Mg 2+ ?