课程名称︰分析化学一
课程性质︰必带
课程教师︰何国荣
开课学院：理学院
开课系所︰化学系
考试日期（年月日）︰2015/1/12
考试时限（分钟）：110
试题 :
Briefly answer the following question (102%)
1. Please calculate the equilibrium constant for strong acis/strong base
titration. (6%)
2. Describe the effect of electrolyte concentration to the concentration
based Ksp. (5%)
3. Describe the assumption and the criteria of the assumption for the
correctness of the following equation. [H+] = Ka[HA]/[H+]. (6%)
4. If the dissociation is less than 5%, show that Ka/CHA is smaller than
2.5*10^-3. (6%)
5. Explain the error due to junction potential in pH measurement. (5%)
6. Explain that it is not practical to titrate an acid or base when its
strength is too weak. (5%)
7. Describe the criteria so that the equation for calculation pH of a
amphiprotic species can be simpled to
√(K1*K2*(CHA-)+K1*Kw)/(K1+CHA-). (6%)
8. Explain that in potentiometry measurement the current should be
negligible. (5%)
9. Explain that buffer solution is not prepared by mixing the calculated
amount of a weak acid and its conjugated base. (5%)
10. Explain that the standard reduction of silver is larger than the standard
reduction of silver chloride. (5%)
11. Explain the advantage of using pH meter in acid-base titration. (5%)
12. Based on completeness of a strong acid-strong base reaction, explain that
titration is not often used in trace analysis. (6%)
13. Explain the sodium error in pH measurement. (5%)
14. Explain the reason of controlling pH in the range of 9-11 if Eriochrome
black T was chosen as the indicator. (5%)
15. Describe the major factor affecting the buffer capacity of a buffer
solution. (5%)
16. Explain that mulitdentate instead of monodentate ligand is used in metal
ion titration. (5%)
17. (a)0.010M HCl (b)0.0001M HCl solutions were titrated with NaOH solution.
Please draw the two titration curves on the same diagram. (6%)
18. Explain that the rate of the reaction is often fast in titration. (5%)
19. Please derive the equation for titration error, if the end point is after
the equivalence point in a strong acid - strong base titration. (6%)