A lab student has the choice of three types of pigment to study for an excercise in quantitative spectrophotometry. She always liked the bright yellow color of ripe bananas, so the pigment responsible for the color was chosen. A solution comprised of 100 mL acetone and 100 mL H2O was used to extract and purify the yellow pigment. The pigment solution was then evaporated to a dry powder, dissolved in methanol and given to the student in this condition.
What would be the appropirate blank to use for the spectrophotometric measurements?
A. Mixture of equal volumes of acetone and H2O
B. Acetone
C. H2O
D. Methanol
E. More information is needed for this determination to be made.
Please select the correct answer and explain why, thanks!
What would be the appropirate blank to use for the spectrophotometric measurements?
A. Mixture of equal volumes of acetone and H2O
B. Acetone
C. H2O
D. Methanol
E. More information is needed for this determination to be made.
Please select the correct answer and explain why, thanks!
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When choosing a blank you want to try to include everything in the blank except for the compound being measured. In this case the pigment is being measured and has been dissolved in methanol. So, the blank must be D. Methanol. In this way any effects due to the methanol will be subtracted from the spectrum (I assume UV/Visible) of the pigment.
Hope this is helpful to you. JIL HIR
Hope this is helpful to you. JIL HIR