1.What was the purpose of measuring the stock solution’s absorbance at different
ID: 92669 • Letter: 1
Question
1.What was the purpose of measuring the stock solution’s absorbance at different wavelengths? Or in other words, why did you need to make an absorbance spectrum for this dye?
2.Explain why you used a blank when using the spectrophotometer. Make certain to explain why you needed to use the blank between each measurement in the first part of the experiment, but only once in the second part of the experiment.
3.You mix up a stock solution of green dye by adding 5 mg of green dye in 100 ml of water and find that there is maximum absorbance of 0.75A at 425nm for this dye.
What wavelengths of light do you expect to be transmitted through this solution (refer to Table 3.1 in your lab manual)?
If you were to add another 2 mg of the green dye to your stock solution would you expect the absorbance at 425nm to be higher or lower than 0.75 A425?
Explanation / Answer
The absorption spectrum is the spectrum that is formed by electromagnetic radiation passing through a medium in which radiation of certain frequencies is absorbed.as different compound absorb light at different wavelength,a spectrophotometer is used to diffrentiate compoundsby analyzing the wavelength pattern absorbed in the given solution.Shorter the wavelength the greater is its energy,and shorter the wavelength the higher is its frequency.
Absorbance spectrophotometry is commonly uesd laboratory technique to determine the concentration of substance in a solution.Due to absorbance of visible light many compounds are coloured..Light with wavelength between 620 to 750 nm is perceived as red light by human eye.White light contain all the visible wavelength of light combined together.When white light is passed through a solution some of the wavelength are transmitted and some are absorbed and the liquid will appear coloured.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.