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Unformatted text preview: CHEM 209 Final Exam 1 00/06
NAME: 1. (16 POINTS) What quantiﬁes axe plotted on the x- and y-axes of: x-axis -axis (a) an absorption spectrum?
(b) a chromatogram? 2. (8 POINTS) Deﬁne the term “retention time”. What is its principal use in GC
analysis? '3. (12 POINTS) Write the equilibrium constant expressions for the following balanced
chemical reactions: (a) 1131904 + 311120 ——> P044 + 31430+
K = (b) Agzso‘. (solid) ——> my + soﬁ
K = (c) 2 mo; + 3 czoﬁ' + 4 OH" ——'—> 2 M1102 (solid) + 6003’“ + 2 H20 K = .-~m———m—_nlp—mmmmm¢mht—w_—-——-——u------- . . 7_-——.——w-w-%——-——— 4. (24 POINTS) Suppose that you are 'ven the task of determining the SCN' content ofa-
blood sample by forming the Fe(SCN) + complex and measuring its absorbance.’ You _
begin by taking a 10.00-mL portion of the blood sample, centriﬁl ' g it, transferring 0.25
ml ofthe clear serum to a ﬂask, and adding 5.00 .ml of 0.20M Fe . The %T ofthis
solution, measured at 450 nm, is 51.5%. A calibration curve, prepared from I"e(SCN)2+
standards, indicates that the Fe(SCN)2+ concentration of the diluted sample solution is 0.064 111M. (a) Calculate the SCN' content (in mM) of the blood sample. SHOW ALL WORK
CLEARLY. (Atomic weight of Fe = 55.85 gram/mole; formula weight of SCN' m 58.08 gram/mole) (b) What is the absorbance of the diluted sample solution? 5. (24 POINTS) Draw block diagrams of each of the following analytical instruments,
labeling all the important components. (a) a gas chromatograph (GC) (b) a visible spectrophotometer (e.g., the Spectronic 20) 6. (16 POINTS) Sketch the shape of the titration curves expected for the following tinntions:
(a) HC] with NaOH _ PH mLNaOH :
(b) Na2CO3 with HCI .
(c) NaOH wjth HC]
(d) KHP with NaOH
mL NaOl-l ‘ﬁmmmmW—Mimmmﬁrm,_-___.____.._..._.__... .. ...
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