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.
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?
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.
a. The donor is a hydrogen atom bonded ti a carbon
b. The more linear the bond, the stronger the interaction
c. The acceptor must be similar in electronegativity to hydrogen
d. It is a type of covalent bond
e. A hydrogen bond is weaker than van der waals forces