1) A chemist discovered four bottles of liquid simply labelled A-D, each
of which contained a different pure organic compound. The compounds were known to be heptan-1-ol, heptanal, heptane and heptene. The chemist put a sample from each bottle through Infrared Spectroscopy and recorded the results below in Table 1.
a) Use the information in the data table (Table 2) to suggest which compound is in which bottle.
b) For each compound justify your conclusion
Table 1 Infrared Spectroscopic Results for unknown samples:
---------------------------------------------------------------------------------------
Bottle----- Infrared Spectroscopy main Troughs (wavelength cm-1)
------------------------------------- 3300
-- A ---------------------------------3000
--------------------------------------1100
------------------------------------750-1000
---------------------------------------------------------------------------------------
---------------------------------------3000
--- B --------------------------------750-1000
---------------------------------------------------------------------------------------
---------------------------------------3000
--- C --------------------------------1650
---------------------------------------750-1000
----------------------------------------------------------------------------------------
----------------------------------------3000
---- D --------------------------------1710
---------------------------------------750-1000
--------------------------------------------------------------------------------------
Table 2 Wavenumber data for different bonds between atoms:
---------------------------------------------------------------------------------------
---------------------------Infrared Absorption Data---------------------------
-----Bond--------------------------------- Wavenumber / cm-1--------------
N – H
(amines) -----------------------------------3300 - 3500
--------------------------------------------------------------------------------------
O – H
(alcohols) ----------------------------------3230 - 3550
-------------------------------------------------------------------------------------
C – H --------------------------------------- 2850 - 3300
-------------------------------------------------------------------------------------
O – H
(acids) --------------------------------------2500 - 3000
------------------------------------------------------------------------------------
C ≡ N --------------------------------------- 2220 - 2260
-----------------------------------------------------------------------------------
C = O --------------------------------------- 1680 - 1750
-----------------------------------------------------------------------------------
C = C --------------------------------------- 1620 - 1680
----------------------------------------------------------------------------------
C – O --------------------------------------- 1000 - 1300
----------------------------------------------------------------------------------
C – C ----------------------------------------- 750 - 1100
-------------------------------------------------------------------------------------
2 answers
heptan-1-ol
----H---H--H---H---H---H--H
-----I----I----I----I----I----I----I
H - C - C - C - C - C - C - C - OH
-----I----I----I-----I----I----I----I
----H---H---H---H---H---H---H
heptanal
----H---H--H---H---H---H---O
-----I----I----I----I----I----I----II
H - C - C - C - C - C - C - C - H
-----I----I----I-----I----I----I
----H---H---H---H---H---H
heptane
----H---H--H---H---H---H--H
-----I----I----I----I----I----I----I
H - C - C - C - C - C - C - C - H
-----I----I----I-----I----I----I----I
----H---H---H---H---H---H---H
heptene
---------------H---H---H---H--H
----------------I----I----I----I----I
H - C = C - C - C - C - C - C - H
-----I----I----I-----I----I----I----I
----H---H---H---H---H---H---H
I do not know what to do.