0 votes
64 views
ago in Analytical Chemistry by (350 points)
What are the specific functional groups present in a given organic compound (unknown substance) which exhibits absorption peaks at 1650 cm^-1 and 1740 cm^-1 in IR spectroscopy and a peak at 220 nm in UV-Vis spectroscopy? Use the graph of absorptivity versus wavelength to determine the identity and concentration of those functional groups.

1 Answer

0 votes
ago by (470 points)
The absorption peaks at 1650 cm^-1 and 1740 cm^-1 in IR spectroscopy suggest the presence of the following functional groups:1. 1650 cm^-1: This peak corresponds to the C=O stretching vibration, which is characteristic of carbonyl groups. It could be an amide, an ester, or a ketone.2. 1740 cm^-1: This peak is also associated with the C=O stretching vibration, but it is more indicative of an ester or an aldehyde functional group.The peak at 220 nm in UV-Vis spectroscopy suggests the presence of a conjugated -system, which could be found in compounds with alternating single and double bonds or aromatic systems.To determine the identity and concentration of the functional groups, you would need to analyze the graph of absorptivity versus wavelength. Look for the molar absorptivity    values at the specific wavelengths mentioned above. Using the Beer-Lambert Law  A =   c  l , where A is the absorbance, c is the concentration, and l is the path length, you can calculate the concentration of the functional groups in the sample. Compare the obtained concentration values with known reference values for different functional groups to identify the specific functional groups present in the unknown compound.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...