4/23/24

Question 1

what is collisional broadening

Answer 1

the time between the collisions affects the excited state lifetime

Question 2

when there is a short time between collisions, how is the peak width affected

Answer 2

the peak will be wider and more broad

Question 3

when there is a long time between collisions, how is the peak width affected

Answer 3

the peak width will be more narrow and small

Question 4

for a gas sample, how is the peak width affected for a higher pressure sample?

Answer 4

the collisional frequency is increased, the time between collisions is decreased so there is a larger/broader peak width

Question 5

for a gas sample, how is the peak width affected for a low pressure sample

Answer 5

the collisional frequency is decreased, the time between collisions is decreased so there is a narrower/smaller peak width

Question 6

between liquids and gases, how do they differ in terms of collisional broadening

Answer 6

liquids will have a higher collisional frequency, therefore less time between collisions and more collisional broadening

gases will have less collisional frequency, therefore more time between collisions and less collisional broadening

Question 7

for the doppler effect, how does the observed frequency of a molecule vary when the molecule is moving away from the detector?

Answer 7

the observed frequency is less than the emitted frequency

Question 8

for the doppler effect, how does the observed frequency of a molecule vary when the molecule is moving toward the detector

Answer 8

the observed frequency is greater than the emitted frequency

Question 9

for molecules at higher temperatures, how is their doppler broadening affected?

Answer 9

the molecules move faster so there is larger doppler broadening

Question 10

for molecules at lower temperatures, how is their doppler broadening affected?

Answer 10

the molecules move slower, so there is a smaller doppler broadening

Question 11

do liquids or gases have more doppler broadening? Why?

Answer 11

gases have more doppler broadening because they have longer distances between collisions

liquids have less doppler broadening because they have shorter distances between collisions

Question 12

how is the doppler effect related to the speed of the molecule

Answer 12

it is proportional to it

Question 13

what is the rigid rotor model

Answer 13

we assume the bond length does not change during rotation