Transferrin (T) -
Molar mass = 81000g/mol - carries 2 Fe3+ ions
Deferrioxxamine B (DB)
molar mass = 650g/mol - carries 1 Fe3+
at wavelength 428
molar absorptivity T = 3240
molar absorptivity DB = 2630
at wavelength 470
molar absorptivity T = 4370
molar absorptivity DB = 2190
A solution of transferrin and desferrioxamine was placed in a cuvet with a path length of
1 cm. The absorbance at 470 nm was 0.42, and the absorbance at 428 nm was 0.40.
Calculate the concentration Fe(III) in transferring, assuming each transferrin binds two
Fe(III)
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I calculated concentration for T at both wavelengths using Beers law and added them to find C=2.19*10^-4M
2.19*10-4 M T * 81000 g/mol = 17.739 g/L T
percent mass of Fe3+ in T is
111.69g/81000g *100%= 0.138%
% Fe3+ in 17.739g T = 0.0245g =4.38*10^-4M Fe3+
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I am not sure if this is correct or if I am even on the right track. There is a second part to the question (which is why I wasn't sure if I needed to use all the information given at the beginning). Any help would be great! thank you
To the person who posted this question, did you get the right answer? I'm looking for the right answer as well. I'm assuming you were in CHMC11. Did you get the right answer in the quiz/midterm/final? Thanks!
Yes, you are on the right track. Your calculation for the concentration of Fe(III) in transferrin (T) seems to be correct.
To recap, you calculated the concentration for T at both wavelengths (428nm and 470nm) using Beer's law and added them to get C = 2.19*10^-4M. Then you found the mass of Fe(III) in transferrin by multiplying the concentration of T with its molar mass (81000 g/mol), which gave you 17.739 g/L T.
Next, you calculated the percent mass of Fe(III) in T by dividing the mass of Fe(III) (0.138 g) by the mass of transferrin (17.739 g) and multiplying by 100%. This gave you 0.138%.
Finally, you calculated the molar concentration of Fe(III) in T by multiplying the percent mass of Fe(III) in T by the molar concentration of T, which gave you 4.38*10^-4M Fe(III).
It seems like you have successfully calculated the concentration of Fe(III) in transferrin based on the given information. If you have any further questions or need help with the second part of the question, please let me know!
To calculate the concentration of Fe(III) in transferrin, you are on the right track. Here's how to proceed based on the given information:
1. Use Beer's Law to calculate the concentration of transferrin (T) at both wavelengths (428 nm and 470 nm). You have already done this and found a concentration of 2.19 × 10^-4 M.
2. Multiply the concentration of transferrin by its molar mass to find the mass of transferrin in grams (in this case, 17.739 g/L).
3. Determine the percentage of Fe(III) in transferrin by dividing the mass of Fe(III) by the mass of transferrin and multiplying by 100 (0.138%).
4. Convert the mass of Fe(III) to moles by dividing by the molar mass of Fe(III) (111.69 g/81000 g/mol) - you have already done this calculation and found 0.0245 g or 4.38 × 10^-4 M.
Therefore, the concentration of Fe(III) in transferrin is approximately 4.38 × 10^-4 M.
Now, if you have a second part to the question, please let me know the details, and I will be happy to help you further.