Infrared Spectroscopy

Identify the bonds which will produce strong absorptions in the IR region of the electromagnetic spectrum.
I. C-O bond
II. C=C bond
III. C=O bond

• I and II only
• I and III only
• II and III only
• I, II and III

Tags

NGSS.HS-PS4-4

The infrared spectrum was obtained from a compound and showed absorptions at 2100 cm^-1,
1700 cm^-1, and 1200 cm^-1.  Identify the compound.

• CH₃COOCH₃
• C₆H₅COOH
• CH₂=CHCH₂OH
• CH≡CCH₂CO₂CH₃

Tags

NGSS.HS-PS4-4

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

Tags

NGSS.HS-PS4-4

What part of the atom or molecule does infrared radiation affect

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

Tags

NGSS.HS-PS1-4

NGSS.HS-PS4-4

The independent variable on an IR spectra is 

• wave length 
• wave number
• frequency squared
• transmission

Tags

NGSS.HS-PS4-1

The dependent variable on an IR spectra is 

• wave length 
• wave number
• frequency
• transmission

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-4

The greater the polarity of a bond the_______________its IR absorption

• weaker
• stronger
• more charged
• smaller the wavenumber

Tags

NGSS.HS-PS4-3

NGSS.HS-PS4-4

Non polar symmetrical molecules 

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

Tags

NGSS.HS-PS4-4

The finger print region is 

• different for each organic compound
•  from 600 - 1400 cm^-1
• both the above

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

• True
• False

Tags

NGSS.HS-PS4-4