M+ equation
M+= n(mass)+n(mass)
M+1 equation
(isotope % natural abundance)
——————————(n)(100)+…(normal % natural abundance
NMR
- calculate degree of unsaturation
- count number of splits in peak
- number of peaks-1= # of H
- draw structure
What is present at 7 on NMR?
benzyl group
What are you identifying in low molecular weight alcohol lab?
characterizing the alcohol as primary, secondary, tertiary, aliphatic, allylic, or benzylic
Aliphatic alcohol
has more than 2 carbons
Allylic alcohol
has double bond
Benzylic alcohol
has a benzen ring
Solubility test
If all seven drops of the alcohol dissolve, indicate the solubility as greater than 10%
Ceric Nitrate test
Positive test- change in color from yellow to orange-red
A positive test is obtained with alcohols contains no more than 10 carbon atoms
Lucas Test
Positive test- visible change/ emulsion
Iodoform Test
Positive test- yellow precipitate is formed
disguises ethanol from all other 1º alcohols, and 2º methyl carbines from all other 2º alcohols
Concentrated HCl Test
Positive test- heat/steam/bubbles produced
tests allylic, benzoic, and 3º
Chromic Anhydride test
Positive test- color change from orange to blue-green
positive test indicates a 1º or 2º alcohol
3,5-dinitrobenzoates
Tells you the melting point
-structure
Preparation of 2,4-dinitrophenylhydrazones
structure
-degree of color will give clue about aldehyde or ketone compound
-range in color from yellow to red
Tollens test
Formation of a sliver mirror on the test tube identifying aldehyde
Iodoform test (ketones and aldehydes)
distinguishes methyl ketones from all other ketones
-gives yellow precipitate
-ONLY exception is acetaldehyde
Bisulfite test
-positive test forms white precipitate
-reacts with aldehydes, cyclic ketones, (less than or equal to eight carbons in the ring), and methyl ketones except methyl aryl ketones
-TWO exceptions are acetone and acetaldehyde which do not give positive test
Lewis acid
electron pair acceptor
Lewis base
electron pair donator
If the aspirin is darker purple it is ______
less pure
If the aspirin is light purple it is _____
more pure
Calculate yield %
Actual yield
—————— X 100
theoretical yield
