Infrared Spectroscopy

A molecule absorbs IR at a wavenumber of 1720 cm^-1.  Which functional group could account for this absorption.
I. aldehydes
II. esters
III. ethers

• I only
• I and II 
• I, II and III 
• none of the above

What part of the atom or molecule does infrared radiation affect

• the nucleus
• the electrons
• the  bonds
• the charge

The greater the polarity of a bond the_______________its IR absorption

• weaker
• stronger
• more charged
• smaller the wavenumber

Non polar symmetrical molecules 

• do not absorb IR radiation
• absorb IR  radiation
• absorb the most IR  radiation
• transmit IR radiation

The fingerprint region is

• different for each organic compound

• from 600 - 1500 cm^-1

• both the above

The actual wavelength which is absorbed by any bond can vary.  

• True
• False

Stronger bonds absorb IR at

• higher wavenumbers

• lower wavenumbers

• in the finger print region

• 600cm^-1

 Mass of attached atoms affect the absorbance of the bond

• True
• False

A molecule has a very broadband at 3200cm^-1 and a sharp band at 1711cm^-1. the molecule is most likely an

• amide

• ester

• alkenol

• carboxylic acid

The infrared spectrum of an organic compound is shown.

Which compound produces this spectrum?

• butanone

• ethanol

• pent-2-ene

• propanoic acid