Question

1. 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 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.

1. electromagnetic radiation with a maximum wavelength of 540 nm (5.4×10^(-7) m) is needed for the study of the photoelectric effect in potassium atoms. what is the approximate frequency that corresponds to this wavelength?

a. 1.8×10^15 s^(-1)
b. 1.6×10^2 s^(-1)
c. 1.9×10^6 s^(-1)
d. 5.6×10^14 s^(-1)

Explanation:

27.

Infrared radiation is associated with molecular vibrations. When a molecule absorbs infrared radiation, it causes transitions to higher - energy vibrational levels. For a carbonyl group, the absorption of infrared radiation leads to an increase in molecular vibrational level associated with the stretching of the carbon - oxygen double bond.

Step1: Recall the formula for the frequency - wavelength relationship

The formula is $c = \lambda
u$, where $c$ is the speed of light ($c= 3\times10^{8}\ m/s$), $\lambda$ is the wavelength, and $
u$ is the frequency.

Step2: Rearrange the formula to solve for frequency

We get $
u=\frac{c}{\lambda}$. Given $\lambda = 540\ nm=5.4\times 10^{-7}\ m$.

Step3: Substitute the values into the formula

$
u=\frac{3\times 10^{8}\ m/s}{5.4\times 10^{-7}\ m}\approx5.6\times 10^{14}\ s^{-1}$

Answer:

C. The absorption of infrared radiation causes the transition to a higher vibrational level associated with the stretching of the carbonyl.

28.