10D.3

Question 1

what is infrared radaiton

Answer 1

it is a part of an electromagnetic spectrum with frequencies below the red light

Question 2

when a molecule absorbs infrared molecules what happens

Answer 2

vibrations:

1. stretching = the bond length increases and decreases
2. bending = the bond angle increases and decreases

Question 3

when a C-H bond absorbs infrared radiation what happens

Answer 3

1. the bond length increases (stretching)

2. the bond angle decreases (bending)

Question 4

when a module absorbs infrared radiation the amount of energy it absorbs depends on

Answer 4

1. the length of the bond
2. the strength of the bond
3. the mass of the atoms involved in the bond
4. the polarity of the molecule (nonpolar = doesn’t absorb energy)

Question 5

how is the infrared radiation spectrum come to be

Answer 5

when a compound is irritated by infrared radiation its bonds would absorb some radiation from parts of the spectrum but not from other

Question 6

what is a transmittance

Answer 6

it is shown in % on the vertical axis and it is the amount of radiation absorbed at a particular wavenumber

Question 7

what is a wavenumber

Answer 7

it is the frequancy of infrared radiation absorbed by a particular bond in a molecule it is on the horizontal axis and it is with units of Cm^-1 and it starts from 4000 - 500

Question 8

what is a feature of an infrared spectrum

Answer 8

it changes after 2000 wavenumber

Question 9

in an infrared spectrum, dips represent?

Answer 9

absorption of infrared radiation

Question 10

what is intensity

Answer 10

it is the amount of infrared absorbed

Question 11

the stronger the intensity

Answer 11

the lower the transmittance

Question 12

when we say abortion is sharp that means

Answer 12

there is a narrow wavenumber

Question 13

when we say abortion is broad that means

Answer 13

there is a wide wavenumber