課程名稱︰分析化學乙上
課程性質︰生技系、農化系必修
課程教師︰劉春櫻
開課學院：理學院
開課系所︰化學系
考試日期（年月日）︰2013年1月11日
考試時限（分鐘）：2小時
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
Analytical Chemistry (Final Examination)
Jan. 11, 2013
I. Make a distinction between: (20%)
1.Activity and activity coefficient
2.Iodimetry and iodometry
3.Thermodynamic and concentration equilibrium constant
4.A galvanic cell and electrolytic cell
5.Standard electrode potential and formal potential
II.Problems
1.How to prepare a (a) carbonate free sodium hydroxide (b) standard
solution? (4%)
2.
(a)Define buffer capacity.
(b)Find the pH of a 1.00 L aqueous solution containing 12.43 of tris (FM
121.14) plus 4.67 g of tris hydrochloride (FM 157.60).
(c)If we add 12.0 mL of 1.00M HCl to the solution in the preceding problem,
what will the new pH be? (pKa=8.07) (8%)
3.Write a charge balance equation for an aqueous solution that contains
NaCl, Ba(ClO4)2 and Al2(SO4)2. (3%)
4.Consider curves for the titration of 0l10M NaOH and 0.010M NH3 with 0.10M
HCl.
(a)Briefly account for the difference between curves for the two titrations.
(b)In what respect will the two curves be indistinguishable? (4%)
5.The most common method for the determining organic nitrogen (eg. Protein;
melamine and cyanuric acid etc.) is the Kjeldahl method. The method, then
is based on a neutralization titration with boric acid as collector. Please
write all the chemical equations involved. (6%)
6.Derive equations that define α0, α1, α2, and α3 for the acid H3AsO4.
(6%)
7.What is the pH of pure water and of 0.1M NaCl? (8%)
(αH+ =900 pm; αOH =350pm; Kw=1.0×10-14.)
8.Explain the unusual properties of the following titration curves
(a)Phosphoric acid
(b)Oxalic acid
(c)Sulfuric acid (6%)
9.What is isoelectric focusing? (8%)
10.Give an example of chelation therapy. (3%)
11.State the purpose of an auxiliary complexing agent in the EDTA titration,
and give an example of its use. (4%)
12.Find the conditional formation constant for Mg(EDTA)2- at pH 9.00.
(log Kr for Mg(EDTA)2- is 8.79; αγ4- at pH 9.00 is 0.041) (3%)
13.Describe how mercury could serve as an indicator electrode of the second
kind for the EDTA anion Y4- , when a small amount of HgY2- is added to a
solution containing Y4-.
[Hint: The formation constant, Kr for HgY2- is very large (6.3×1021), so
the concentration of the complex remains essentially constant over
a large range of Y4- concentrations.] (5%)
14.Calculate the formation constant Kr for Ag(CN)2-. If the cell develops a
potential of -0.625V. where E°SCE = -0.224V
SEC|| KAg(CN)2 (7.50×10-3 M), CN- (0.0250M)| Ag (6%)
15.Describe the source of pH dependence in a glass membrane electrode. (6%)
16.How is an oxidation-reduction titration curve generated through the use
of standard electrode potentials for the analyte species (Fe2+) and the
volumetric titrant (Ce4+)? (6%)
17.Give an example for the potentiomertric biosensing of proteins with
ultrasensitive ion-selective microelectrode and nanoparticle labels. (10%)
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※ 編輯: jhangyu 來自: 203.67.112.217 (01/14 01:59)