課程名稱︰分析化學丁
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︰園藝系
考試日期（年月日）︰2007/11/22
考試時限（分鐘）：10:20~12:30
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
Briefly answer the following questions: (101 points)
1 In the analysis of chocolate, describe and "explain" the steps used in
sample preparation. 6%
2 Find the absolute and percent relative uncertainty and express each answer
with a reasonable number of significant figures. 4%
9.43(±0.05)x{[6.2(±0.2)x10^-3]+[4.1(±0.1)x10^-3]}=?
3 One 25mL Class A volumetric pipet (±0.03mL) is used to deliver a total of
50mL. "Explain" the total uncertainty. 4%
4 Explain that the pH of a solution needs to be reported with two decimal
places. 4%
5 Describe the precedures to improve the accuracy due to (a). systemic error;
(b). random error. 6%
6 Explain that no difference in the two population means is used as the bull
hypothesis in the comparison of two means. 5%
7 (a). Describe the precedures for the determination of limit of detection.
(b). "Explain" the critical step(s) in the precedures. 8%
8 Explain the relationship between the use objectives and quality assurance.
4%
9 Describe the condition(s) of using a paired t-test. 4%
10 Describe the condition of using the method of standard addition. 4%
11 Explain that sample concentration is an important factors in the
construction of a calibration curve. 4%
12 Describe the relationship (or no relationship) between trueness, accuracy,
bias, random error, determination error, systemic error, presicion and
indetermination error. 6%
13 One measurement was performed on each standard solution. 8%
(a) Explain the assumption that standard deviation of signal can be
canculated.
(b) The importance of the assumption in (a). to the construction of a
calibration curve.
14 Explain that the conjugate base of a weak acid is always a weak base. 4%
15 Draw the titration curve for the reaction of 0.002000M weak acid (pKa 6.27)
with NaOH. (Indicate the initial pH, the infection point, the equivalance
point and the final pH) 8%
16 Explain that it is difficult to titrate a diluted weak acid. 4%
17 Explain the condition that the equation (1) can be simplified to equation
(2). 6%
[H+]=√((Ka2 CHA- +Kw)/(1+ CHA-/Ka1)) (1)
[H+]=√(Ka1 x Ka2) (2)
18 Explain the major factors to the buffer capacity of a weak acid and its
conjugate base. 4%
19 Explain the reason(s) that a buffer solution is not prepared by calculating
and weighting what to mix. 4%
20 Describe the buffer capacity of a solution prepared by a strong base. 4%
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