Question

one type of organic molecule can be converted to another type of organic molecule through an oxidation - reduction process, as represented in the diagram above. which of the following best explains why infrared spectroscopy is an appropriate method to confirm that the product contains a carbonyl?
a the absorption of infrared radiation causes the nonbonding electrons on oxygen to transition into a higher electronic energy level.
b the absorption of infrared radiation leads to an increase in molecular vibrational level associated with the stretching of the carbonyl.
c the absorption of infrared radiation causes the electrons in the pi bond to transition to a higher bonding energy level.
d infrared radiation leads to an increase in the molecular rotational level associated with the carbonyl as the axis of rotation.

Explanation:

Infrared spectroscopy works based on the absorption of infrared radiation by molecules. When a molecule absorbs infrared radiation, it causes an increase in its vibrational energy levels. The carbon - oxygen double bond (carbonyl) in a molecule has characteristic stretching vibrations that can be detected by infrared spectroscopy. When infrared radiation of the appropriate frequency is absorbed, the molecular vibrational level associated with the stretching of the carbonyl increases.

Answer:

B. The absorption of infrared radiation leads to an increase in molecular vibrational level associated with the stretching of the carbonyl.