Lv 2335 points

# Olivia

Cyclohexanone exhibits its strongest IR peak at 5.86 µm, and at this wavelength a linear relationship exists between absorbance and concentration

a. Identify the part of the molecule responsible for the

absorbance at this wavelength.

Question

b. Suggest a solvent that would be suitable for a quantitative

analysis of cyclohexanone at this λ.

c. A solution of cyclohexanone (2.0 mg/ml) in the solvent

selected in part (b) exhibits an absorbance of 0.40, in a cell

with a path length of 0.025 mm. What is the detection limit

for this comp under these conditions if the noise associated

with the spectrum of the solvent is 0.001 absorbance units?

• ### How to calculate transmittance from concentration?

Im not sure how to do these

3. A 10 mM solution has a transmittance of 45%. Calculate the transmittance of a 20mM solution at the same wavelength and optical pathlength.

4. Two colored solution, C and D contain different dyes. Let the transmittances of these two solutions be TC and TD respectively, when measured in a 1-cm cell at a given wavelength. Express the transmittance TCD of the mixture of equal volumes of C and D, measured under the same conditions, in terms of TC and TD.

D-proteins are comprised of D-amino acids, rather than the typical L-amino acids. Such “mirror image” proteins are attractive therapeutics because they are not recognized by proteases, and thus have a longer half-life in the body. Provide a brief explanation for why the peptide bonds in D-proteins resist cleavage by proteases.