CHEM 210 FINAL EXAM QUESTIONS AND CORRECT ANSWERS, COMPLETE SOLUTION 2024.

CHEM 210 FINAL EXAM QUESTIONS AND CORRECT ANSWERS, COMPLETE SOLUTION 2024. In particular gravimetric analysis, the precipitate of bariums ulfate was weighed before it was completely dried. The likely impact of this error on the calculated result is. A. Minimal, because the mass of water is very low. B. Lower result than correct value. C. Higher result than correct value. D. Minimal, because calculation assumes a hydrated sample is produced. E. All of the above are not correct. C. Higher result than correct value. Atomic spectroscopy is... A. Measurement of intensity of emitted light at a particular wavelength from the atoms that are excited thermally. B. Measurement of absorbance of emitted light at particular wavelength from atoms excited thermally. C. Measurement of intensity of emitted light at particular wavelength from the atoms that are excited by monochromatic light. D. Measurement of intensity of absorbed light at a particular wavelength from the atoms that are excited thermally. E. None of the above. A. Measurement of intensity of emitted light at a particular wavelength from the atoms that are excited thermally. In many countries, fish with more than 0.500 ppm mercury is considered unsafe. In one experiment, a 0.750 g piece of tuna was appropriately treated and made up to 10.0 mL solution. This solution returned an absorbance of 0.70. Using the calibration graph below, what can be concluded from this analysis? A. The tuna does not contain mercury. B. The concentration of mercury in the tuna is less than 0.500 ppm and it can be eaten safely. C. The concentration of mercury is exactly equal to 0.500 ppm and may or may not be safe to eat. D. The concentration of mercury in the tuna is greater than 0.500 ppm and it should not be eaten. E. None of the above. D. The concentration of mercury in the tuna is greater than 0.500 ppm and it should not be eaten. Of the following compounds, which would you expect to elute first from a nonpolar gas chromatographic column? A. Methanol (CH3OH) B. Ethanol (CH3CH2OH) C. n-Propanol (CH3CH2CH2OH) D. n-Butanol (CH3CH2CH2CH2OH) E. n-Pentanol (CH3CH2CH2CH2CH2OH) A. Methanol (CH3OH) Separation of ions in mass spectrometer take place on the basis of which of the following? A) Mass B) Charge C) Molecular weight D) Mass to charge ratio E) None of the above. D) Mass to charge ratio Which of the following are examples of systematic errors? I. Weighing a precipitate on an electronic balance. II. Consistently reading burette volumes from the top of the meniscus. III. Using an incorrectly labelled standard solution in a titration. A. I, II and III B. I and III only C. I and II only D. II and III only E. III only D. II and III only What is the molar concentration and absolute uncertainty of a solution made by dissolving 1.065 ± 0.001 g of Na2CO3 in 50.0 ± 0.3 mL of distilled water? A. 0.201± 0.050 mol/L B. 0.201± 0.001 mol/L C. 0.201± 0.301 mol/L D. 0.201± 0.694 mol/L E. None of these B. 0.201± 0.001 mol/L When using an internal standard, the identity of the standard is : A. Different than the analyte and of known concentrations. B. The same as the analyte and at the same concentration. C. It could be the same or different relative to the analyte. D. It should be the same as the analyte but of different (known) concentrations. E. All above are not correct. A. Different than the analyte and of known concentrations. The weight percent concentration of an aqueous phosphoric acid is 28%; this means that (assuming the density of the solution is 1 g/mL): A. 1 L of this solution contains 28 mL of phosphoric acid B. 100 mL of this solution contains 28 g of phosphoric acid C. 1 mL of this solution contains 28 g of phosphoric acid D. 28 g of phosphoric acid dissolved in 100 mL of water E. 1 L of this solution has a mass of 28 g of phosphoric acid B. 100 mL of this solution contains 28 g of phosphoric acid A 0.1500 M HCl solution was prepared on a day when the temperature was 20 C. What is concentration of the solution when used the next day at 27 C? The density of water is 0.9982071 g/mL at 20 C and 0.9965162 g/mL at 27 C. A. 0.1508 M B. 6.632 M C. 0.1503 M D. 6.653 M E. 0.1497 M E. 0.1497 M For a specific reaction, which of the following statements can be made about K, the equilibrium constant? A.It always remains the same at different reaction conditions (concentrations and temperature). B. It increases if the concentration of one of the products is increased. C. It changes with changes in the temperature.