GRE Chemistry Domain 1: Analytical Chemistry Welcome to your GRE Chemistry Domain 1: Analytical Chemistry 1. GRE Chemistry: Analytical Chemistry In chromatography, what is the term for the ratio of the time a solute spends in the stationary phase to the time it spends in the mobile phase? A. Retention factor B. Elution strength C. Distribution coefficient D. Partition coefficient None 2. GRE Chemistry: Analytical Chemistry Which technique would be most appropriate for separating and identifying small amounts of different proteins in a complex mixture? A. Gas chromatography B. Mass spectrometry C. High-performance liquid chromatography (HPLC) D. Capillary electrophoresis None 3. GRE Chemistry: Analytical Chemistry What is the primary purpose of a guard column in HPLC? A. To increase the resolution of the separation B. To protect the analytical column from contamination C. To pre-separate components in the sample D. To enhance the detection sensitivity None 4. GRE Chemistry: Analytical Chemistry In analytical chemistry, what is the primary advantage of using a flame ionization detector FID in gas chromatography? A. High sensitivity to inorganic compounds B. Ability to provide structural information C. High sensitivity to organic compounds D. Compatibility with aqueous samples None 5. GRE Chemistry: Analytical Chemistry In UV-Vis spectroscopy, what does the term 'bathochromic shift' refer to? A. Shift towards shorter wavelengths B. Increase in absorption intensity C. Shift towards longer wavelengths D. Decrease in absorption intensity None 6. GRE Chemistry: Analytical Chemistry Which of the following is a common use of differential scanning calorimetry DSC in analytical chemistry? A. Identifying unknown compounds B. Determining the purity of a substance C. Measuring heats of reaction D. Analyzing the molecular weight of polymers None 7. GRE Chemistry: Analytical Chemistry In mass spectrometry, what is the significance of the base peak in a mass spectrum? A. It is the peak with the highest m/z ratio. B. It represents the molecular ion peak. C. It is the peak with the highest intensity. D. It indicates the presence of isotopes. None 8. GRE Chemistry: Analytical Chemistry What is the principle behind isocratic elution in chromatography? A. Gradual change in mobile phase composition B. Constant mobile phase composition C. Variable flow rate of the mobile phase D. Alternating mobile phase solvents None 9. GRE Chemistry: Analytical Chemistry In electroanalytical methods, what does a cyclic voltammogram primarily measure? A. The concentration of the analyte B. The potential difference between two electrodes C. The current as a function of the applied potential D. The resistance of the solution None 10. GRE Chemistry: Analytical Chemistry In ion chromatography, what is the role of the suppressor? A. To separate different ions based on their size B. To enhance the detection of specific ions C. To reduce the background conductivity of the eluent D. To increase the flow rate of the mobile phase None 11. GRE Chemistry: Analytical Chemistry In potentiometric analysis, what does a Nernstian response of an electrode indicate? A. The electrode is contaminated B. The electrode is responding ideally to changes in analyte concentration C. The measurement is affected by temperature changes D. The electrode has reached its end of life None 12. GRE Chemistry: Analytical Chemistry What is the primary advantage of using Fourier-transform infrared (FTIR) spectroscopy over dispersive IR spectroscopy? A. Higher sensitivity B. Better resolution C. Faster data acquisition D. Ability to analyze solid samples None 13. GRE Chemistry: Analytical Chemistry In analytical chemistry, what principle does thermogravimetric analysis TGA primarily rely on? A. Change in optical properties with temperature B. Change in electrical conductivity with temperature C. Change in mass as a function of temperature D. Change in magnetic properties with temperature None 14. GRE Chemistry: Analytical Chemistry What is the primary purpose of using an internal standard in quantitative analytical chemistry? A. To validate the accuracy of the instrument B. To compensate for sample loss during analysis C. To calibrate the measurement scale D. To correct for variations in sample volume None 15. GRE Chemistry: Analytical Chemistry In ion-exchange chromatography, what is the primary function of the stationary phase? A. To allow free movement of the mobile phase B. To absorb all the ions from the solution C. To selectively bind ions based on their charge D. To act as a pH buffer for the mobile phase None 16. GRE Chemistry: Analytical Chemistry Which analytical technique is most suitable for determining the molecular weight of high polymers? A. Nuclear magnetic resonance (NMR) B. Size exclusion chromatography (SE C. C) Ultraviolet-visible spectroscopy (UV-Vis) D. X-ray fluorescence (XRF) None 17. GRE Chemistry: Analytical Chemistry What is the primary advantage of using a diode-array detector in HPLC? A. It allows simultaneous detection of multiple wavelengths. B. It increases the sensitivity for a single wavelength. C. It reduces the time required for analysis. D. It enhances the separation efficiency of the column. None 18. GRE Chemistry: Analytical Chemistry In electroanalytical chemistry, what is the main purpose of a reference electrode? A. To provide a stable and known potential B. To measure the current flow in the cell C. To catalyze the redox reaction D. To increase the conductivity of the electrolyte None 19. GRE Chemistry: Analytical Chemistry In fluorescence spectroscopy, what causes the Stokes shift? A. The difference in energy between the absorbed and emitted photons B. The change in concentration of the fluorescent species C. The interference from other light sources D. The temperature effect on the fluorescence intensity None 20. GRE Chemistry: Analytical Chemistry What is the primary use of a chelating agent in titrimetric analysis? A. To increase the speed of the titration reaction B. To form a stable complex with the analyte C. To act as a primary standard D. To adjust the pH of the solution None 1 out of 20 Time is Up! Time's up
