Test Bank Quantitative Chemical Analysis, 10th Edition Daniel C. Harris A+

_ chemical analysis is the measurement of how much of a chemical substance is present. __________ chemical analysis is the determination of what is present in a sample.

2. Which of the following analyses is NOT quantitative?

3. Chemical Abstract is the most comprehensive source for locating articles published in chemistry journals. ___________ is software that accesses Chemical Abstract.

4. Sampling is the process in which

5. A sample with a uniform chemical composition is a ___________ sample.

6. A(n) __________ sample is a sample in which the chemical composition differs from place to place.

7. When extracting a sample with a liquid, the liquid is __________ from the sample.

8. A(n) _____________ is used to grind solids into smaller particles.

9. ______________ is the substance being measured during a chemical analysis.

10. The liquid above the packed solid following a centrifugation is the ___________.

11. A(n) __________ is a suspension of a solid in a liquid.

12. ____________ is the series of procedures applied to a sample prior to analysis.

13. An aliquot is

14. For separations performed using a chromatography column, the plot of detector response versus time is a(n) __________, and the area under the peak is _________ to the quantity of compound passing through the detector.

15. A(n) ___________ is a plot of detector response as a function of analyte concentration. The curve is constructed using ___________ containing known concentrations of the analyte of interest.

16. ______________ is the process of procuring a representative sample to analyze.

17. Solid-phase extraction is a sample preparation technique. Which statement(s) is/are NOT true for an aqueous solid-phase extraction?

1. Solid-phase extraction separates analyte from the sample matrix using a chromatography stationary phase.
2. An aliquot of the aqueous sample is applied to the solid-phase extraction tube. It is washed with additional sample and then a water wash.
3. The analyte sticks to the column, and the water wash removes all species that do not adhere to the column.
4. An organic solvent is used to wash the analyte from the column.
5. The organic phase containing the analyte is evaporated to dryness, and the solid is dissolved in water, ready for analysis.

18. Which is NOT a general step in the analytical process?

19. The purpose of replicate measurements is to assess the __________ in the analysis and to guard against __________ in the analysis of a single aliquot.

20. __________ are repeated measurements to assess variability in an analysis and to guard against gross error in the analysis of a single aliquot.

21. Which statement is NOT true?

22. __________ occurs when a species other than analyte increases or decreases the analytical signal and makes it appear that the concentration is greater or less than the real concentration.

23. __________ is the transformation of an interfering species into a form that is not detected.

24. Ca²⁺ in lake water can be measured with a reagent called EDTA. However, the presence of Al³⁺ will provide a false signal because it reacts with EDTA as well. The method of adding excess F⁻ to minimize the effects of Al³⁺ on the Ca²⁺ determination is called

25. Chemists use the term __________ to refer any chemical of interest.

26. A calibration curve for the determination of aspirin is constructed from known concentration aspirin solutions (mg/mL) and the HPLC peak areas for each standard. If the equation of the best-fit line is y = 12.565x − 0.71, what is the concentration for an unknown that has a peak area of 83.5?

27. The allicin concentration in a garlic extract sample was determined using HPLC. A calibration curve prepared using allicin standards of known concentration (M) has an equation of the best-fit line of y = 24 376x + 8.4. What is the molar concentration of allicin in the garlic extract sample if it has a signal of 88.9?

28. The spectrophotometric analysis of a series of permanganate standards (mM) at 525 nm gave a calibration equation of y = 2.492 5x + 0.091. If an unknown sample has an absorbance reading of 0.654, what is the millimolar concentration of permanganate in the unknown solution?

29. The fluorescence quantum yield measurement results of quinine sulfate in 0.1 M H₂SO₄ solution showed that there was a linear relationship between the integrated photoluminescence intensity and absorbance of quinine sulfate. The relationship is described by the equation y = 1.28 ´ 10⁸x – 780 102, where y is the integrated photoluminescence intensity and x is the absorbance of quinine sulfate. If the sample has an absorbance of 0.045, what is its photoluminescence intensity?

30. Inorganic anions can be analyzed by capillary electrophoresis with conductivity detection. A calibration curve for nitrate was constructed by plotting the signal (μV) as a function of nitration concentration (μM), resulting in an equation of y = 498x + 3.28. If a sample contains 62.5 mM nitrate ions, what would be the signal of nitrate in the sample?