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What are the steps to using a spectrophotometer?
- Prepare sample in cuvette. 2. Select appropriate wavelength using the monochromator. 3. Place cuvette in spectrophotometer. 4. Measure absorbance or transmittance. 5. Use Beer-Lambert Law to determine concentration.
How do you determine concentration using the Beer-Lambert Law?
- Measure absorbance (A) of the solution. 2. Know the molar absorptivity () and path length (b). 3. Use the formula A = bc to solve for concentration (c).
What is the difference between absorbance and transmittance?
Absorbance: amount of light absorbed by the sample. Transmittance: amount of light that passes through the sample.
What is the effect of increasing the concentration of a solution on its absorbance (assuming constant path length)?
The absorbance increases proportionally.
What happens if the wrong wavelength of light is used in spectrophotometry?
The absorbance measurement will be inaccurate, leading to an incorrect concentration determination.
What is the effect of using a cuvette with a longer path length?
The absorbance increases proportionally, according to Beer-Lambert Law.