※ [本文轉錄自 NTU-Exam 看板] 作者: Jman208 (→ 171G8) 看板: NTU-Exam 標題: [試題] 96上 何國榮 分析化學乙上 期中考 時間: Wed Nov 14 16:28:37 2007 課程名稱︰分析化學乙(上) 課程性質︰分析化學 課程教師︰何國榮 開課學院：農學院 開課系所︰農化系 考試日期（年月日）︰Nov. 14, 2007 考試時限（分鐘）：10:20am - 12:15pm 是否需發放獎勵金：是 （如未明確表示，則不予發放） 試題 : 總分 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，老師後面有附上 T-table, F-table, 跟計算中會用到的公式 -------------------------------------end-------------------------------------- --

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