Infrared Spectroscopy

Question 1

what does infrared energy cause bonds to do, and how do we use this?

Answer 1

infrared energy causes bonds to vibrate, each bond in a molecule vibrates at a fixed frequency so we can use this to work out what bonds a molecule contains.

Question 2

what are two particular bonds to look out for?

Answer 2

C=O and O-H

Question 3

what should you note if C=O is present?

Answer 3

if present there will be a strong peak at about 1700cm^1, and will almost always be the strongest peak on the spectrum
(present in aldehydes, ketones, carboxylic acids ect.)

Question 4

If O-H is present, what should be noted?

Answer 4

• broad peak on the left
• C-H also comes on the left, but will be sharp not broad