chapters 13, 14, 16

Question 1

Absorption of what type of radiation results in ionization?

Answer 1

x-rays

Question 2

Absorption of what type of radiation results in electronic transitions?

Answer 2

ultraviolet light

Question 3

Absorption of what type of radiation results in transitions among allowed rotational motions?

Answer 3

microwaves

Question 4

Absorption of what type of radiation results in transitions among allowed vibrational motions?

Answer 4

infrared light

Question 5

Absorption of what type of radiation results in transitions among allowed nuclear magnetic spin
states?

Answer 5

radio waves

Question 6

The frequency of the stretching vibration of a bond in IR spectroscopy depends on what two quantities?

Answer 6

masses of the atoms and the stiffness of the bonds

Question 7

In a mass spectrum, the peak of the greatest abundance is the ______ peak.

Answer 7

base

Question 8

The mass spectrum of a compound containing M+ and M+2 peaks in a 1:1 ratio contains

Answer 8

bromine

Question 9

The mass spectrum of a compound containing M+ and M+2 peaks in a 3:1 ratio contains

Answer 9

chlorine

Question 10

When 1,3-butadiene reacts with CH2=CHCN, the product mixture is

Answer 10

A racemic mixture

Question 11

The Diels-Alder reaction is a concerted reaction. This means that

Answer 11

All bond making and bond breaking occurs simultaneously

Question 12

What does the chemical acronym HOMO stand for?

Answer 12

Highest Occupied Molecular Orbital

Question 13

What four features distinguish conjugated dienes from isolated dienes?

Answer 13

[1] The C – C single bond joining the two double bonds is unusually short.
[2] Conjugated dienes are more stable than similar isolated dienes.
[3] Some reactions of conjugated dienes are different than reactions of isolated double
bonds.
[4] Conjugated dienes absorb longer wavelengths of ultraviolet light.

Question 14

What four features do all Diels-Alder reactions have in common?

Answer 14

[1] They are initiated by heat; that is, the Diels–Alder reaction is a thermal reaction.
[2] They form new six-membered rings.
[3] Three pi bonds break, and two new C – C sigma bonds and one new C – C pi bond form.
[4] They are concerted; that is, all old bonds are broken and all new bonds are formed in
a single step.

Question 15

Conjugated dienes and polyenes absorb light in the 200-400 nm wavelengths, making them ideal
for use as

Answer 15

sunscreens