L4 Rich: raman spectroscopy Flashcards Preview

1st Year sem 2 : Forensic Analysis > L4 Rich: raman spectroscopy > Flashcards

Flashcards in L4 Rich: raman spectroscopy Deck (17):
1

what happens with light during Raman spectroscopy?

most of the light is absorbed and transmitted but some is scattered.

2

How can scattering of the light be observed?

It can be observed at a right angle to the incident beam

3

when scattering frequency is equal to incident frequency it is known as?

Rayleigh scattering

4

1% of scattered intensity occurs at a different frequency to the incident frequency.what is this called?

Raman scattering

5

what is Raman interactions dependent on?

existence of polarisable bonds

6

are larger atoms more polarisable?

yes

7

what can be used as a solvent tin Raman spectroscopy?

water

8

whats the rule of mutual exclusion when there is centre of symmetry?

If a molecule has a centre of symmetry then Raman active vibrations are infrared inactive and vice versa.

9

whats the rule of mutual exclusion when there is no centre of symmetry?

If there is no centre of symmetry, some vibrations may be both Raman and infrared active

10

Vibrations with a change in dipole moment give ___ _____

IR bands

11

Highly ____ bonds ____ intense IR bands

polar
intense

12

Highly polar bonds give ____ spectra of ____ intensity

Raman
Low

13

what samples can be used with RS?

gas, liquid, solid

14

is RS qualitative or quantitative?

mainly qualitative

15

is RS destructive?

no

16

where can RS be applied?

Drugs Paints Fibres Inks Explosives

17

what is RS complementary to?

IR spectroscopy