AP MCQ 03DEFGHKLM PART 2 Question 01: Which of the following aqueous solutions could be analyzed using a colorimeter and the application of the Beer-Lambert law? NaCl(aq) MgBr2(aq) NiSO4(aq) Na2SO4(aq) Question 02: Ultraviolet (UV) radiation and Infrared (IR) radiation are two types of radiation that are used in chemical spectroscopy. Since UV and IR have differing ranges of frequency, the chemicals that are exposed to these types of radiation react in different ways. Which of the following is the correct combination of expected behavior in each case? UV: causes outer electrons to be promoted; IR: causes bonds to bend & stretch UV: causes bonds to bend & stretch; IR: causes outer electrons to be promoted UV: causes outer electrons to be promoted; IR: causes outer electrons to be promoted UV: causes bonds to bend & stretch; IR: causes bonds to bend & stretch Question 03: In a Beer's law experiment, typically, which wavelength should be chosen as the incident light? The wavelength of light with the lowest absorbance The wavelength of light with the highest absorbance The wavelength of light with the highest transmittance Any wavelength can be chosen Question 04: Consider the data below that shows the variation in the absorbance of light of a colored solution, against the concentration of that solution. What does the graph suggest about the transmittance of the incident light as concentration increases? Transmittance is directly proportional to concentration Transmittance is inversely proportional to concentration Since transmittance is not plotted on the graph it is not possible to tell Transmittance and concentration have no relationship Question 05: The concentration of some solutions can be determined by the use of a spectrophotomer or colorimter. Which of the following techniques/considerations are necessary in order to produce reliable data? The use of saturated solutions only The constant use of only one wavelength of incident light Periodic calibration of the instrument using a known standard The use of colorless solutions Question 06: Microwaves typically cause molecules to undergo what type of behavior? Electronic transitions of outer electrons Molecular rotation Electronic transitions of core electrons Molecular bending and stretching (vibration) Question 07: During a Beer-Lambert law experiment, the cuvette is handled by a student resulting in the transfer of greasy fingerprints on to the surface of the container. What is the effect on, and the reason for, the change in the calculated value for concentration of the solution under test, when it is compared to the actual (real) value of concentration? The calculated value will be too high, since the absorbance will be artificially high The calculated value will be too high, since the absorbance will be artificially low The calculated value will be too low, since the absorbance will be artificially high The calculated value will be too low, since the absorbance will be artificially low Δ
