Choose the one answer that best answers the question.
 |
1 | |
The visible portion of the electromagnetic spectrum occurs between ___ nm and ___ nm. |
| | A) | 1, 10 |
| | B) | 10, 300 |
| | C) | 400, 740 |
| | D) | 800, 1200 |
|
|
2 | |
Which part of the spectrophotometer is adjusted to select the desired wavelength? |
| | A) | light source |
| | B) | filter |
| | C) | sample |
| | D) | photodetector |
|
|
3 | |
To establish a standard curve for a chemical, the spectrophotometer wavelength is set on which value? |
| | A) | the lowest wavelength possible |
| | B) | the highest wavelength possible |
| | C) | the wavelength at which the chemical's absorption value is the lowest |
| | D) | the wavelength at which the chemical's absorption value is the highest |
|
|
4 | |
A blank contains the ___ but not the dissolved chemical. |
| | A) | solvent |
| | B) | solute |
| | C) | filter |
| | D) | absorption spectrum |
|
|
5 | |
What is the function of the photodetector? |
| | A) | It adjusts the wavelength passing through the sample. |
| | B) | It adjusts the intensity of the light source. |
| | C) | It converts light energy into electrical energy. |
| | D) | It displays the amount of light absorbed in absorbance or transmittance values. |
|
|
6 | |
The blank used to calibrate the spectrophotometer for testing the absorbance spectrum of chlorophyll contained ___. |
| | A) | water |
| | B) | acetone |
| | C) | cobalt chloride |
| | D) | chlorophyll |
|
|
7 | |
Using a standard curve, if you know the abosorbance of an unknown sample, what else can be determined about the unknown? |
| | A) | the wavelength of maximum absorbance |
| | B) | the molecular weight of the sample |
| | C) | the concentration of the sample |
| | D) | the identity of the sample |
|
|
8 | |
Using the figure of the standard curve in the lab manual, if the concentration of a sample is 20 mg/mL, then roughly what is the absorbance? |
| | A) | 0.8 |
| | B) | 0.8 lumens |
| | C) | 0.8 lumens/mg |
| | D) | 1.2 |
|
|
9 | |
Basically, what is the path of light through a spectrophotometer? |
| | A) | meter, photodetector, filter, sample, light source |
| | B) | meter, filter sample, photodetector, light source |
| | C) | light source, filter, sample, photodetector, meter |
| | D) | light source, sample, filter, photodetector, meter |
|
|
10 | |
Basically, what is the function of an absorption spectrum? |
| | A) | It converts light energy into electrical energy. |
| | B) | It is a graph of a chemical relating the absorbance to wavelength. |
| | C) | It is a graph of a chemical relating the absorbance to concentration. |
| | D) | It is the amount of radiation retained by a sample. |
|
2002 McGraw-Hill Higher Education