Analysing IR spectrum.

IR looks at how infrared light interacts with a molecule, measuring the vibration of atoms. Bonds are continuously vibrating and moving around, much like two balls connected by a spring. This spring system is described by Hookes Law, frequency is proportional to the force constant (the stiffness of the spring). Therefore, an increase in bond strength an increase in frequency required to vibrate the bond. An IR spectrum usually consists of the fingerprint region - typically made up of the weaker bonds C-C, C-O etc. Double bonds are stronger due to a greater overlap of orbitals and therefore appear higher on the spectrum, similarly triple bonds are even stronger. Hydrogen bonds are very strong and therefore appear at a high frequency, however in a liquid each hydrogen bond is in a slightly different environment, therefore each have a very slightly different frequency - this (normally) gives the distinctive broad peak.

LW
Answered by Lucy W. Chemistry tutor

2079 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

In what conditions does sodium chloride conduct electricity and why?


What is the difference between a nucleophile and an electrophile?


What is the difference between E-Z isomers and optical isomers?


Describe how you test for an aldehyde or ketone and distinguish between the two.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning