※ [本文转录自 NTU-Exam 看板] 作者: Jman208 (→ 171G8) 看板: NTU-Exam 标题: [试题] 96上 何国荣 分析化学乙上 期中考 时间: Wed Nov 14 16:28:37 2007 课程名称︰分析化学乙(上) 课程性质︰分析化学 课程教师︰何国荣 开课学院：农学院 开课系所︰农化系 考试日期（年月日）︰Nov. 14, 2007 考试时限（分钟）：10:20am - 12:15pm 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 总分 114 1. (a) The purpose of sampling (b) The strategy for sampling of a segregated heterogeneous material. 2. In the analysis of Caffeine from chocolate, sugar was not removed before HPLC analysis. Explain that sugar did not interfere with the analysis. 3. A class-A volumetric flask has a certified tolerance. What is the purpose of calibration of the volumetric flask? 4. What do the symbols "TD" and "TC" mean on volumetric glassware? 5. (a) Explain standard reference materials. (b) The utility of standard reference materials. 6. The strategy for reducing the uncertainty due to (a) systematic error (b) random error. 7. (a) Find the absolute and percent relative uncertainty and express each answer with a reasonable number of significant figures. [6.2(±0.2) - 4.1(±0.1)] ÷9.43(±0.05) = ? (b) State whether the errors in the following condition are random or systematic: A 10-mL buret consistently delivers 1.98±0.01mL when drained from exactly 0 to exactly 2 mL and consistenty delivers 2.03±0.02mL when drained rom 2 to 4 mL. 8. For pH = 5.21±0.03, what is the relative uncertainty of [H+]? 9. (a) The null hypothesis of a F test (b) The reason of chhosing the null hypothesis in (a). 10.The principal concept of finding systematic error using a t-test. 11.For a data to be used in a court, what is the most important characteristics of the data? 12.Students measured the concentration of HCl in a solution by titrating with differen indicators to find the end point. Is the difference between indicators Methyl red and Bromocresol green significant at 95% confidence level? ┌─────────┬─────────────────┬─────────┐ │ Indicator │Mean HCl concentraion (±std.dev.)│ # of measurements│ ├─────────┼─────────────────┼─────────┤ │ Methyl red │ 0.08686 ±0.00098 │ 18 │ ├─────────┼─────────────────┼─────────┤ │ Bromocresol green│ 0.08641 ±0.00113 │ 29 │ └─────────┴─────────────────┴─────────┘ _ 13. (a) The assumption for the equation μ = X±(ts)/√(n) (b) In calibration curve, one measurement was performed on each standard solution, explain the assumption the data can be used to calculate the standard deviation of signal 14. Explain that five data points are often used in the construction of a calibration curve 15. The drawback of the following equation. Ax/[X] = F(As/[S]) 16. The action one should take if matrix effect was found in the construction of a calibration curve. 17. (a) List the equation for the limit of detection if the α error is 5% (b) Explain the rate of β error under the condition of (a)? 18. (a) What is quality assurance? (b) The purpose of method validation. 19. Descrive the solubility behavior of PbI2 if KI was added continuoisly to the solution Ksp PbI2(s) ←───→ Pb^2+ + 2I^- Ksp = [Pb^2+][I^-]^2 = 7.9x10^-9 K1 PB^2+ + I^- ←───→ PbI^1+ K1 = [PbI^1]/[Pb^2+][I^-] = 1.0x10^2 β2 PB^2+ + 2I^- ←───→ PbI2(aq) β2 = [PbI2(aq)]/[Pb^2+][I^-]^2 = 1.4x10^3 β3 PB^2+ + 3I^- ←───→ PbI3^- β3 = [PbI3^-]/[Pb^2+][I^-]^3 = 8.3x10^3 β4 PB^2+ + 4I^- ←───→ PbI4^2- β4 = [PbY4^2-]/[Pb^2+][I^-]^4 = 3.0x10^4 最後，老师後面有附上 T-table, F-table, 跟计算中会用到的公式 -------------------------------------end-------------------------------------- --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.112.249.241 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 123.194.235.122