Reminder: These notes are meant to supplement, not replace, the laboratory manual.
Qualitative Analysis 3 Notes
Application and History
Very frequently a chemist is asked to identify an unknown material. It may be the
product of a reaction, some abandoned chemical in a lab, or a suspicious
substance found in a public place. Since the mid-1950’s this task was made
much easier by the invention and development of many instrumental techniques.
You may have experienced this first time when passing through airport security
and the TSA officer asks to swab your luggage. They are analyzing for minute
traces of explosives. Last week a series of wet chemistry (solutions and
glassware) tests were carried out on an unknown to determine the functional
groups present. In today’s lab the same unknown will be subjected to a series of
instrumental analyses: IR, 1H NMR and 13C NMR. The correct interpretation of
the resulting data will allow the exact structure, not simply the function group
present, to be determined.
Review the notes associated with IR (from CHEM 2230L) and NMR. The details will not
be repeated here.
The IR data can be used to corroborate the functional group identification made during
Qualitative Analysis 2. Use the provided boiling point information to narrow down
the possible compounds from the provided list of possible materials found below.
(Paper lists will also be available in the laboratory.) Finally use the 13C and 1H
NMR to determine the exact structure of the unknown.
Possible Unknowns for Qualitative Analysis 2 and 3
Class
Aldehyde
Aldehyde
Aldehyde
methyl ketone
Aldehyde
Alcohol
Aldehyde
Alcohol
methyl ketone
Alcohol
Alcohol
Ketone
Aldehyde
Aldehyde
Aldehyde
Ketone
Alcohol
Name
propanal
ethanedial
propenal
propanone
isobutyraldehyde
methanol
butanal
ethanol
2-butanone
2-propanol
2-methyl-2-propanol
2,3-butanedione
methoxyethanal
3-methylbutanal
2-methylbutanal
3-methyl-2-butanone
1-propanol
Boiling point (0 C)
50
50
52
56
64
66
75
78
80
83
83
88
92
93
93
94
97
Alcohol
alcohol
Acid
Alcohol
methyl ketone
Ketone
Aldehyde
Aldehyde
Ketone
Alcohol
hydrocarbon
Alcohol
Alcohol
Ketone
Alcohol
Aldehyde
Acid
Alcohol
methyl ketone
methyl ketone
Alcohol
Alcohol
Alcohol
Alcohol
Alcohol
Alcohol
Aldehyde
Ketone
Ketone
Alcohol
Alcohol
Alcohol
methyl ketone
Aldehyde
Ketone
Alcohol
Alcohol
Ketone
Alcohol
Alcohol
Aldehyde
Alcohol
hydrocarbon
Ketone
2-propene-1-ol
2-butanol
methanoic acid
2-methyl-2-butanol
2-pentanone
3-pentanone
2-butenal
pentanal
3,3-dimethyl-2-butanone
2-methyl-1-propanol
toluene
2,2-dimethyl-1-propanol
3-methyl-2-butanol
1-methoxy-2-propanone
3 pentanol
2-methylpentanal
ethanoic acid
1-butanol
3-methyl-2-pentanone
4-methyl-2-pentanone
2-pentanol
3,3-dimethyl-2-butanol
2,3-dimethyl-2-butanol
3-methyl-3-pentanol
2-methyl-2-pentanol
2-methoxyethanol
2-pentenal
3-hexanone
2,4-dimethyl-3-pentanone
2-methyl-3-pentanol
2-methyl-1-butanol
3-methyl-1-butanol
2-hexanone
hexanal
cyclopentanone
4-methyl-2-pentanol
3-methyl-1-butanol
5-hexen-2-one
3-methyl-2-butanol
2-ethoxyethanol
3-methyl-2-butenal
3-hexanol
ethylbenzene
4-methyl-3-hexanone
97
100
101
102
102
102
103
104
106
108
111
113
114
115
116
116
118
118
118
119
120
120
120
123
123
125
125
125
125
128
129
129
129
131
131
132
132
132
134
135
135
136
136
136
Ketone
Alcohol
Alcohol
hydrocarbon
Alcohol
Alcohol
Acid
Acid
Alcohol
Alcohol
Ketone
Acid
ketone
Alcohol
Alcohol
Alcohol
Aldehyde
Ketone
Alcohol
hydrocarbon
Alcohol
Alcohol
Acid
Ketone
Aldehyde
Alcohol
Alcohol
Alcohol
Acid
Ketone
Aldehyde
Aldehyde
Acid
Acid
Ketone
Acid
Aldehyde
Ketone
Aldehyde
Ketone
Alcohol
Aldehyde
Ketone
Alcohol
4-methyl-2-hexanone
2,2-dimethyl-1-butanol
1-pentanol
p-xylene
2-hexanol
2,4-Dimethyl-3-pentanol
propanoic acid
propenoic acid
cyclopentanol
3,3-dimethyl-1-butanol
3-methylcyclopentanone
propynoic acid
4-heptanone
2,3-dimethyl-1-butanol
2-methyl-1-pentanol
2-ethyl-1-butanol
2-hexenal
2-heptanone
4-methyl-1-pentanol
1-methylethylbenzene
3-methyl-1-pentanol
4-heptanol
2-methylpropanoic acid
Cyclohexanone
heptanal
1-hexanol
cyclohexanol
2-heptanol
2-methylpropenoic acid
2-methyl-3-cyclopentenone
1-cyclohexanecarboxaldehyde
2-ethylhexanal
butanoic acid
2,2-dimethylpropanoic acid
2-methylcyclohexanone
3-butenoic acid
butanedial
3-methylcyclohexanone
octanal
4-methylcyclohexanone
furfuryl alcohol
2-ethyl-2-pentenal
2-octanone
4-methyl-1-hexanol
136
137
138
138
139
140
141
141
141
143
143
144
144
145
148
149
150
151
153
153
154
154
155
155
156
159
160
160
161
161
162
163
164
164
166
169
170
170
171
171
172
173
173
174
Alcohol
Acid
Aldehyde
Phenol
Alcohol
Alcohol
Aldehyde
Ketone
Aldehyde
Aldehyde
Phenol
Alcohol
Ketone
Alcohol
Aldehyde,
phenol
Alcohol
Alcohol
Ketone
Phenol
Alcohol
Phenol
Alcohol
methyl ketone
Phenol
Ketone, ester
Ketone
Alcohol
Phenol
methyl ketone
Phenol
Phenol
aldehyde
aldehyde
methyl ketone
aldehyde
methyl ketone
aldehyde
Phenol
aldehyde
aldehyde
1-heptanol
3-methylbutanoic acid
benzaldehyde
phenol
1-octanol
1,2-propanediol
5-methylfurfural (5-methyl-2carbaldehyde furan)
5-nonanone
pentanedial
nonanal
2-methylphenol
3,5,5-trimethyl-1-hexanol
cyclooctanone
1,2-ethanediol
2-hydroxybenzaldehyde
176
177
179
183
185
187
187
2-nonanol
3,7-dimethyl-1,6-octadien-3-ol
2-propylcyclohexanone
4-methylphenol
1-phenylethanol
3-methylphenol
benzyl alcohol
acetophenone
2-methoxyphenol
ethyl 4-oxopentanoate
1,5-dimethylcyclohexen-3-one
2-decanol
2,4-Dimethylphenol
phenylacetone
3-Ethylphenol
4-chlorophenol
4-ethylbenzaldehyde
3-phenylpropanal
4'-methylacetophenone
m-anisaldehyde
4'-chloroacetophenone
dodecanal
1,2-dihydroxybenzene
(catechol)
p-anisaldehyde
4-ethoxybenzaldehye
198
199
199
202
203
203
205
205
205
206
209
211
212
214
217
220
221
224
226
230
232
238
245
187
189
190
192
193
196
197
197
248
255
Revised: September 10, 2013, S.L. Weaver