WorksheetsIR SPECTROSCOPY
Total questions: 17
Worksheet time: 17mins
Name
Class
Date
1.
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. aldehydes
II. esters
III. ethers
a)
I only
b)
I and II
c)
I, II and III
d)
none of the above
2.
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. C-O bond
II. C=C bond
III. C=O bond
a)
I and II only
b)
I and III only
c)
II and III only
d)
I, II and III
3.
What part of the atom or molecule does infrared radiation affect
a)
the nucleus
b)
the electrons
c)
the bonds
d)
the charge
4.
The independent variable on an IR spectra is
a)
wave length
b)
wave number
c)
frequency squared
d)
transmission
5.
The greater the polarity of a bond the_______________its IR absorption
a)
weaker
b)
stronger
c)
more charged
d)
smaller the wavenumber
6.
Non polar symmetrical molecules
a)
do not absorb IR radiation
b)
absorb IR radiation
c)
absorb the most IR radiation
d)
transmit IR radiation
7.
The finger print region is
a)
different for each organic compound
b)
from 600 - 1400 cm-1
c)
both the above
8.
The actual wavelength which is absorbed by any bond can vary.
a)
True
b)
False
9.
Stronger bonds absorb IR at
a)
higher wave numbers
b)
lower wave numbers
c)
in the finger print region
d)
600cm-1
10.
Mass of attached atoms affect the absorbance of the bond
a)
True
b)
False
11.
A molecule has a broadband at 3200cm-1 and sharp band at 1711cm-1. the molecule is most likely an
a)
amide
b)
ester
c)
alkanol
d)
carboxylic acid
12.
A molecule has a band at 3500cm-1 and sharp band at 1711cm-1. the molecule is most likely an
a)
amide
b)
ester
c)
alkanol
d)
carboxylic acid
13.
Which of the following molecules will not show infrared spectrum?
a)
H2
b)
HCI
c)
CH4
d)
H20
14.
What is the relation between wave number of IR absorption and the reduced mass?
a)
Wave number is directly proportional to reduced mass
b)
Wave number is inversely proportional to reduced mass
c)
Wave number is independent of the reduced mass
d)
Wave number is directly proportional to square of reduced mass
15.
In which bending vibration, two atoms approach each other with respect to central atom
a)
Scissoring
b)
Rocking
c)
Wagging
d)
Twisting
16.
In which bending vibration, two atoms move up and down the plane with respect to central atom
a)
Scissoring
b)
Rocking
c)
Wagging
d)
Twisting
17.
What is the range of finger prin region?
a)
2000cm-1 to 1660cm-1
b)
1500cm-1 to 400cm-1
c)
2550cm-1 to 2000cm-1
d)
3600cm-1 to 2870cm-1
100 %
