課程名稱︰分析化學一
課程性質︰系上必修
課程教師︰林萬寅
開課系所︰化學系
考試時間︰10/30
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1.How many grams of (24.5±0.2) wt% NaF (Fw = 49.0; neglect its uncertainty)
4+
are required to react with (20.0 ± 0.1) mL of (0.0200 ± 0.0002) M Th
4+ -
by the reaction Th + 4F → ThF4(s) 8%
2.(A) The densities of distilled water at 20度, air and steel weight are
0.99705, 0.0012 and 8.000 g/mL, respectively. Calculate specific volume
of distilled water at 20度 (corrected for buoyancy). (B) An empty 25-mL
pipet weighs 30.1234g. When the pipet is filled to the mark with distilled
water and weighed again in the air at 20度, the mass is 55.4468g. What is
the true volume of pipet at 20度? 10%
3.Find the absolute uncertainty and express each answer with correct number
of significant figures. 12%
(a) (5.25±0.05)÷[(8.0±0.2)－(3.0±0.1)]
______________________________
√ 2
(3.48±0.04) －(2.54±0.04)
(b) ───────────────────
6.4 ± 0.2
-8
┌ (4.68±0.02)×10 ┐
(c) log │ ────────────│
└ 0.0246 ± 0.0004 ┘
4.A protein is known to contain 20.60 wt% of nitrogen . Two laboratories
analyzed the nitrogen content of this protein and yielded the following
results. 25%
Lab n wt% N (Cl at 50% probabillity)
──────────────────────────────────
A 4 20.20 ~ 21.84
B 6 19.48 ~ 21.08
(a) Find the standard deviations of each lab.
(b) Calculate the pooled standard deviation from these two labs.
(c) Do the standard deviations of the two labs differ from each other at
95% confidence level?
(d) Does the result of lab A differ from the theoretical value at 95%
confidence level?
(e) Do the results of the two labs differ from each other at 95% confidence
level? (use the pooled standard deviation to do the comparison).
→ o o
5.For the reaction 2HBr(g)← H2(g) +Br2(g), △G = -84.0 kJ/mol and △H < 0
at 1400K. A vessel is filled will 500 Pa HBr, 4000 Pa H2 and 3000 Pa Br2
at 1400K. Answer the following questions. 15%
(a) Find the equilibrium constant for the reaction at 1400K.
(b) Will the reaction proceed to the left or the right to reach equilibrium?
(c) Calculate the pressure (in Pa) of each species in the vessel at
equilibrium.
(d) If the mixture at equilibrium is compressed to half its original volume,
what direction will the reaction proceed to reestablish equilibrium?
(e) If the mixture at equilibrium is heated from 1400K to 1410K, will HBr be
formed or consumed in order to reestablish equilibrium?
+ 2+
6.A 10.0 mL solution containing 0.100 M Ag and 0.100 M Hg2 was titrated
-16
with 0.100 M KCN to precipitate AgCN (Ksp = 2.2 * 10 ) and Hg2(CN)2
-40
(Ksp = 5.0 * 10 ) 15%
+ 2+
(a) Which metal ion, Ag or Hg2 , will precipitate first? Explain.
(b) Calculate pCN after addition of 15.0, 25.0, and 30.0 mL of KCN.
7.Answer the following questions. 15%
(a) Describe the method of standard addition.
(b) Describe the principle of adsorption indicator used in the precipitation
+
titration involving Ag .
(c) Define the following acid-base theories. (i) Arrhenius
(ii) Bronsted-Lowry (iii) Lewis.
Values of Student's t
────────────────────────────────────
degree of freedom Condience level (%)
50 90 95
──────────────────────────────
1 1.000 6.314 12.706
2 0.816 2.920 4.303
3 0.765 2.353 3.182
4 0.741 2.132 2.776
5 0.727 2.015 2.571
6 0.718 1.943 2.447
7 0.711 1.895 2.365
8 0.706 1.860 2.306
9 0.703 1.833 2.262
10 0.700 1.812 2.228
Critical values of F at 95% confidence level
──────────────┬────────────────────────
Degrees of freedom for s2│ Degrees of freedom for s1
│ 2 3 4 5 6
──────────────┼────────────────────────
2 │ 19.0 19.2 19.2 19.3 19.3
3 │ 9.55 9.28 9.12 9.01 8.94
4 │ 6.94 6.59 6.39 6.26 6.16
5 │ 5.79 5.41 5.19 5.05 4.95
──────────────┼────────────────────────
6 │ 5.14 4.76 4.53 4.39 4.28
7 │ 4.74 4.35 4.12 3.97 3.87
8 │ 4.46 4.07 3.84 3.69 3.58
9 │ 4.26 3.86 3.63 3.48 3.37
10 │ 4.10 3.71 3.48 3.33 3.22
──────────────┴────────────────────────
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※ 編輯: falchion 來自: 140.112.7.59 (11/02 17:18)