Question: What is the effect of stationary phase

> Why do you think the values of bonds issued by Asian governments declined during the Asian crisis? Why do you think the values of Latin American bonds declined in response to the Asian crisis?

> What factors affect the future movements in the value of the euro against the dollar?

> Explain why a public forecast by a respected economist about future interest rates could affect the value of the dollar today. Why do some forecasts by well-respected economists have no impact on today’s value of the dollar?

> What is the expected relationship between the relative real interest rates of two countries and the exchange rate of their currencies?

> Assume that the Japanese government relaxes its controls on imports by Japanese companies. Other things being equal, how should this affect (a) the U.S. demand for Japanese yen, (b) the supply of yen for sale, and (c) the equilibrium value of the yen?

> Assume that the U.S. income level rises at a much higher rate than does the Canadian income level. Other things being equal, how should this affect (a) the U.S. demand for Canadian dollars, (b) the supply of Canadian dollars for sale, and (c) the equi

> The New Zealand dollar’s spot rate was equal to $0.60 last month. New Zealand conducts much international trade with the United States, but the financial (investment) transactions between the two countries are negligible. Assume the following conditions

> The country of Neeland has stable and predictable international trade flows with the United States. Neeland periodically makes the news because its government might have problems repaying its debt owed to local banks. The value of its currency (the “nee”

> The country of Vezot has massive capital flows with the United States because it has no restrictions on the movement of investment funds into or out of the country. Its inflation rate just increased substantially, while the U.S. inflation rate remains un

> The country of Zars has large capital flows with the United States. It has no trade with the United States and will not have trade with the United States in the future. Its interest rate is 6 percent, the same as the U.S. interest rate. Its rate of infla

> The country of Quinland has large capital flows with the United States. It has no trade with the United States and will not have trade with the United States in the future. Its interest rate is 6 percent, the same as the U.S. interest rate. You expect th

> During the Asian crisis, Hong Kong and China successfully intervened (by raising their interest rates) to protect their local currencies from depreciating. Nevertheless, these countries were also adversely affected by the Asian crisis. Why do you think t

> Here are exchange rates for the Japanese yen and British pound at the beginning of each of the last five years. Your firm wants to determine which currency is more volatile as it assesses its exposure to exchange rate risk. Estimate the volatility of eac

> Assume U.S. interest rates fall relative to British interest rates. Other things being equal, how should this affect (a) the U.S. demand for British pounds, (b) the supply of pounds for sale, and (c) the equilibrium value of the pound?

> Last year a dollar was equal to 7 Swedish kronor, and a Polish zloty was equal to $0.40. Today, the dollar is equal to 8 Swedish kronor, and a Polish zloty is equal to $0.44. By what percentage did the cross exchange rate of the Polish zloty in Swedish k

> Assume that inflation is zero in the United States and in Europe and will remain at zero. U.S. interest rates are presently the same as in Europe. Assume that economic growth in the United States is presently similar to that occurring in Europe. Assume t

> Assume you want to determine whether the monthly movements in the Polish zloty against the dollar are more volatile than the monthly movements in some other currencies against the dollar. The zloty was valued at $0.4602 on May 1, $.4709 on June 1, $0.488

> Kurnick Co. expects that the pound will depreciate from $1.70 to $1.68 in one year. It has no money to invest, but it could borrow money to invest. A bank allows the company to borrow either $1 million or £1 million for one year. Kurnick can borrow dolla

> The country of Luta has large capital flows with the United States. It has no trade with the United States and will not have trade with the United States in the future. Its interest rate is 6 percent, the same as the U.S. interest rate. Its rate of infla

> Assume that the level of capital flows between the United States and the country of Zeus is negligible (close to zero) and will continue to be negligible. A substantial amount of trade takes place between the United States and the country of Zeus. The ma

> You reside in the United States and are planning to make a one-year investment in Germany during the next year. Because the investment is denominated in euros, you want to forecast how the euro’s value may change against the dollar over the one-year peri

> Assume that the level of capital flows between the United States and the country of Krendo is negligible (close to zero) and will continue to be negligible. In contrast, a substantial amount of trade occurs between the United States and the country of Kr

> In most cases, a weak local currency is expected to stimulate the local economy. Yet, it appeared that the weak currencies of Asian countries adversely affected their economies. Why do you think the weakening of the home currencies did not initially impr

> Was the depreciation of the Asian currencies during the Asian crisis due to trade flows or capital flows? Why do you think the degree of movement over a short period may depend on whether the reason is trade flows or capital flows?

> Define a) Isocratic elution. b) Gradient elution. c) Normal-phase packing. d) Reversed-phase packing. e) Bonded-phase packing f) Chiral chromatography. g) Ion-pair chromatography. h) Eluent-suppressor column. i) Gel filtration. j) Gel permeatio

> List the types of substances to which each of the following chromatographic methods is most applicable: a) Gas-liquid. b) Liquid-liquid. c) Ion. d) Adsorption. e) Gel permeation. f) Affinity. g) Chiral.

> An HPLC method was developed for the separation and determination of ibuprofen in rat plasma samples as part of a study of the time course of the drug in laboratory animals. Several standards were chromatographed and the following results obtained: Next

> Two components in an HPLC separation have retention times that differ by 22 s. The first peak elutes in 10.5 minutes, and the peak widths are approximately equal. The void time, tM, was 63 s. Use a spreadsheet to find the minimum number of theoretical pl

> Although temperature does not have nearly the effect on HPLC separations that it has on GC separations, it nonetheless can play an important role. Discuss how and why temperature might or might not influence the following separations: a) A reversed-phas

> The ideal detector for GC is described in Section 30A-4. Which of the eight characteristics of an ideal GC detector are applicable to HPLC detectors? What additional characteristics would be added to describe the ideal HPLC detector?

> Which of the GC detectors in Table 30-1 are suitable for HPLC? Why are some of these unsuitable for HPLC? Table 30-1:

> Mass spectrometry is an extremely versatile detection system for gas chromatography. Describe the major reasons why it is more difficult to combine HPLC with mass spectrometry than it is to combine GC with mass spectrometry.

> Describe the differences between single-column and suppressor-column ion chromatography.

> Describe two types of pumps used in HPLC. What are the advantages and disadvantages of each?

> Why are fragments often produced with electron ionization?

> What is the major difference between isocratic elution and gradient elution? For what types of compounds are these two elution methods most suited?

> What types of species can be separated by GC but not by HPLC?

> Describe the difference between gel-filtration and gel-permeation chromatography.

> Describe the fundamental difference between ion exchange and size-exclusion chromatography.

> Describe the fundamental difference between adsorption and partition chromatography.

> Indicate the order of elution of the following compounds from a normal-phase packed HPLC column: a) Ethyl acetate, acetic acid, dimethylamine. b) Propylene, hexane, benzene, dichlorobenzene.

> What kind of mixtures are separated by gas-solid chromatography?

> Why is gas-solid chromatography not used as extensively as gas-liquid chromatography?

> How do gas-liquid and gas-solid chromatography differ?

> For the data given in Example 30-1, compare the method of external standards to the internal standard method. Plot the analyte peak height versus percent analyte, and determine the unknown without using the internal standard results. Are your results any

> How do electron and electrospray ionization sources differ? What are the advantages and disadvantages of each?

> Peak areas and relative detector responses are to be used to determine the concentration of the five species in a sample. The area normalization method described in Problem 30-20 is to be used. The relative areas for the five gas chromatographic peaks ar

> One method for quantitative determination of the concentration of constituents in a sample analyzed by gas chromatography is the area normalization method. In this method, complete elution of all the sample constituents is necessary. The area of each pea

> List the variables that lead to a) Band broadening b) Band separation in gas-liquid chromatography.

> What are the advantages of fused-silica capillary columns compared with glass or metal columns?

> What properties should the stationary phase liquid for gas chromatography possess?

> Why are gas chromatographic stationary phases often bonded and cross-linked? What do these terms mean?

> How do the following capillary columns differ? a) PLOT columns b) WCOT columns c) SCOT columns

> What are megabore open tubular columns? Why are they used?

> What are hyphenated gas chromatographic methods? Briefly describe three hyphenated methods.

> Why are detection limits for ICPMS often lower with double-focusing mass spectrometers than with quadrupole mass spectrometers?

> What are the principal advantages and the principal limitations of each of the detectors listed in Problem 30-10? Detectors listed in Problem 30-10: a) Thermal conductivity, b) Flame ionization, c) Electron capture, d) Thermionic, e) Photoionization.

> Describe the principle on which each of the following GC detectors are based: a) Thermal conductivity, b) Flame ionization, c) Electron capture, d) Thermionic, e) Photoionization.

> What is meant by temperature programming in gas chromatography?

> What variables must be controlled if satisfactory qualitative data are to be obtained from chromatograms?

> Describe the physical differences between capillary and packed columns. What are the advantages and disadvantages of each?

> What is meant by temperature programming in gas chromatography?

> Describe a chromatogram, and explain what type of information it contains.

> Explain how you would use one of the flow meters in Figure 30-2. Figure 30-2:

> How do strong- and weak-acid synthetic ion-exchange resins differ in structure?

> Define a) Elution. b) Eluent. Diffusion. c) Stationary phase. d) Distribution constant. e) Retention time. f) Longitudinal g) Selectivity factor. h) Plate height.

> What are the requirements of an internal standard in ICPMS?

> Name three methods based on mechanical phase separation.

> What does the term salting out a protein mean? What is the salting in effect?

> What does the term salting out a protein mean? What is the salting in effect?

> What is a collector ion, and how is it used?

> Referring to Problem 29-28, calculate the resolution for a) Methylcyclohexene and methylcyclohexane. b) Methylcyclohexene and toluene. c) Methylcyclohexane and toluene. Data from Problem 29-28: The following data were obtained by gas-liquid chromatogr

> The following data were obtained by gas-liquid chromatography on a 40-cm packed column: Calculate a) An average number of plates from the data. b) The standard deviation for the average in (a). c) An average plate height for the column.

> From the data in Problem 29-24, calculate for species C and D a) The resolution. b) The length of column necessary to separate the two species with a resolution of 1.5. Data from Problem 29-24: The following data are for a liquid chromatographic colum

> From the data in Problem 29-24, calculate for species B and C a) The resolution. b) The selectivity factor. c) The length of column necessary to separate the two species with a resolution of 1.5. d) The time required to separate the two species on th

> From the data in Problem 29-24, calculate for A, B, C, and D a) The retention factor. b) The distribution constant. Data from 29.24: The following data are for a liquid chromatographic column: A chromatogram of a mixture of species A, B, C, and D pro

> The following data are for a liquid chromatographic column: A chromatogram of a mixture of species A, B, C, and D provided the following data: Calculate a) The number of plates from each peak. b) The mean and the standard deviation for n. c) The pla

> What types of interferences are encountered in ICPMS?

> A packed column in gas chromatography had an inside diameter of 5.0 mm. The measured volumetric flow rate at the column outlet was 48.0 mL/min. If the column porosity was 0.43, what was the linear flow velocity in cm/s?

> An open tubular column used for gas chromatography had an inside diameter of 0.15 mm. A volumetric flow rate of 0.85 mL/min was used. Find the linear flow velocity in cm/s at the column outlet.

> An aqueous solution containing MgCl2 and HCl was analyzed by first titrating a 25.00-mL aliquot to a bromocresol green end point with 17.53 mL of 0.02932 M NaOH. A 10.00-mL aliquot was then diluted to 50.00 mL with distilled water and passed through a st

> Describe the preparation of exactly 1.00 L of 0.1000 M HCl from primary-standard-grade NaCl using a cation-exchange resin.

> The total cation content of natural water is often determined by exchanging the cations for hydrogen ions on a strong-acid ion-exchange resin. A 25.0-mL sample of a natural water was diluted to 100 mL with distilled water, and 2.0 g of a cation-exchange

> To determine the equilibrium constant for the reaction 25.0 mL of a 0.0100 M aqueous solution of I2 was extracted with 10.0 mL of CHCl3. After extraction, spectrophotometric measurements revealed that the I2 concentration of the aqueous layer was 1.12 x

> A 0.150 M aqueous solution of the weak organic acid HA was prepared from the pure compound, and three 50.0-mL aliquots were transferred to 100.0-mL volumetric flasks. Solution 1 was diluted to 100.0 mL with 1.0 M HClO4, solution 2 was diluted to the mark

> If 30.0 mL of water that is 0.0500 M in Q is to be extracted with four 10.0-mL portions of an immiscible organic solvent, what is the minimum distribution coefficient that allows transfer of all but the following percentages of the solute to the organic

> What is the minimum distribution coefficient that permits removal of 99% of a solute from 50.0 mL of water with a) Two 25.0-mL extractions with toluene? b) Five 10.0-mL extractions with toluene?

> What volume of n-hexane is required to decrease the concentration of Z in Problem 29-12 to 2.00 x 10-5 M if 40.0 mL of 0.0200 M Z is extracted with a) 50.0-mL portions of n-hexane? b) 25.0-mL portions? c) 10.0-mL portions?

> What are the y-axis and the x-axis of an ordinary mass spectrum?

> What volume of n-hexane is required to decrease the concentration of X in Problem 29-11 to 1.00 x 10-4 M if 25.0 mL of 0.0500 M X is extracted with a) 25.0-mL portions? b) 10.0-mL portions? c) 2.0-mL portions?

> The distribution coefficient for Z between n-hexane and water is 5.85. Calculate the percent of Z remaining in 25.0 mL of water that was originally 0.0550 M in Z after extraction with the following volumes of n-hexane: a) One 20.0-ml portion. b) Two 10

> The distribution constant for X between n-hexane and water is 8.9. Calculate the concentration of X remaining in the aqueous phase after 50.0 mL of 0.200 M X is treated by extraction with the following quantities of n-hexane: a) One 40.0-ml portion. b)

> Describe two general methods for improving the resolution of two substances on a chromatographic column.

> Describe a method for determining the number of plates in a column.

> What are the major differences between gas-liquid and liquid-liquid chromatography?

> Repeat the calculations in Problem 29-32 assuming KM = 5.81 and KN = 6.20. Data from Problem 29-32: From distribution studies, species M and N are known to have water/hexane distribution constants of 5.99 and 6.16 (K = [X]H2O/[X]hex), where X = M or N.

> From distribution studies, species M and N are known to have water/hexane distribution constants of 5.99 and 6.16 (K = [X]H2O/[X]hex), where X = M or N. The two species are to be separated by elution with hexane in a column packed with silica gel contain

> If VS and VM for the column in Problem 29-28 are 19.6 and 62.6 mL, respectively, and a nonretained air peak appears after 1.9 minutes, calculate a) The retention factor for each compound. b) The distribution constant for each compound. c) The selectiv

> List the variables that lead to band broadening in chromatography.

> What function does the ICP torch serve in mass spectrometry?