1.In Experiment 1, where was the peak absorbance for the yellow dye?
- 420 mm
- 420 nm
- 500 mm
- 500 nm
2.Where was the peak absorbance for the red dye?
- 500 nm
- 420 mm
- 500 mm
- 420 nm
3.Where was the peak absorbance for the blue dye?
- 640 nm
- 640 mm
- 500 mm
- 500 nm
4.At the peak absorbance for the yellow dye, which of the following statements is true?
- There was also moderate (>10%) absorbance of the blue dye at this wavelength.
- There was also moderate (>10%) absorbance of the red dye at this wavelength.
- The absorbance of all three dyes was equal at this wavelength.
- There absorbance peaks of all of the dyes were well separated without any overlap.
5.What color was the wavelength of peak absorbance of the blue dye?
- red
- purple
- yellow
- blue
6.What color was the wavelength of peak absorbance of the yellow dye?
- yellow
- green
- red
- purple-blue
7.What color was the wavelength of peak absorbance of the red dye?
- red
- yellow-orange
- blue-green
- purple
8.In Experiment 2, what was the absorbance of the Yellow 5 dye in cuvette 1 at lambda max?
- 0.55
- 0.37
- 0.49
- 0.12
9.What was the absorbance of the Yellow 5 dye in cuvette 2 at lambda max?
- 0.55
- 0.49
- 0.12
- 0.37
10.What was the absorbance of the Yellow 5 dye in cuvette 3 at lambda max?
- 0.25
- 0.55
- 0.12
- 0.37
11.What was the absorbance of the Yellow 5 dye in cuvette 4 at lambda max?
- 0.49
- 0.37
- 0.25
- 0.12
12.What was the concentration of the food dyes in cuvette 1? You can use the dilution formula below.
C1V1 = C2V2
- 0.020 mM
- 0.20 mM
- 0.010 mM
- 0.0050 mM
13.What was the concentration of the food dyes in cuvette 2? You can use the dilution formula below.
C1V1 = C2V2
- 0.20 mM
- 0.0050 mM
- 0.020 mM
- 0.015 mM
14.What was the concentration of the food dyes in cuvette 3? You can use the dilution formula below.
C1V1 = C2V2
- 0.020 mM
- 0.0050 mM
- 0.20 mM
- 0.010 mM
15.What was the concentration of the food dyes in cuvette 4? You can use the dilution formula below.
C1V1 = C2V2
- 0.010 mM
- 0.020 mM
- 0.0050 mM
- 0.20 mM
16.In Experiment 3, what was the absorbance of the drink mix at the lamba max wavelength for the yellow dye? Choose the closest answer.
- 1.28
- 0.35
- 0.84
- 0.06
17.What was the absorbance of the drink mix at the lamba max wavelength for the red dye? Choose the closest answer.
- 0.73
- 0.01
- 1.12
- 0.25
18.Given that the molar mass of the Yellow 5 dye is equal to 534.36 g/mol, how many grams of Yellow 5 food dye were in the 0.235 L solution of drink mix? Remember that you diluted your original solution ten fold before measuring its absorbance. Choose the closest answer.
- 0.0075 g
- 0.0050 g
- 0.018 g
- 0.0018 g
19.Given that the molar mass of the Red 40 dye is equal to 496.42 g/mol, how many grams of Red 40 food dye were in the 0.235 L solution of drink mix? Remember that you diluted your original solution ten fold before measuring its absorbance. Choose the closest answer.
- 0.0045 g
- 0.011 g
- 0.0011 g
- 0.085 g
20.What is the mass percent of the Yellow 5 food dye in the orange powder? % mass = (mass of dye / mass of powder) x 100
- 12%
- 2.2%
- 0.36%
- 0.036%
21.What is the mass percent of the Red 40 food dye in the orange powder? % mass = (mass of dye / mass of powder) x 100
- 0.22%
- 0.022%
- 1.8%
- 0.061%
22.The observation that the absorbance is directly proportional to the concentration of dye is a statement of which law?
- Beer’s Law
- Boyle’s Law
- Dalton’s Law
- Avogadro’s Law
23.Given the peak absorbance wavelength of the Blue 1 dye, which of the following statements is true?
- The peak absorbance occurs at a wavelength that is different from the color that is perceived because we see the wavelengths that are reflected.
- The peak absorbance wavelength is the same as the wavelength that we see because we see the wavelengths that are absorbed by the sample.
- The peak absorbance wavelength is the same as the wavelength that we see because we see the wavelengths that are reflected.
- The peak absorbance occurs at a wavelength that is different from the color that is perceived in the eye because we see the wavelengths that are absorbed by the sample.
24.Below is a graph of the absorbance of the yellow dye at the peak absorbance wavelength as a function of the concentration of the yellow dye. What is the observed relationship between the absorbance and the concentration?
- Linear, with the absorbance increasing as a function of concentration.
- Linear, with the absorbance decreasing as a function of concentration.
- Hyperbolic, with the absorbance increasing as a function of concentration.
- The absorbance is independent of the concentration.