Experiment organic chemistry

1. Experiment: Tests for Functional Groups
In biology, there are several organic functional groups that are important for function. Tests for
four of these functional groups (hydroxyl, carbonyl, carboxyl, and amino) will be investigated in
this experiment.
Materials and Apparatus:
Isopropyl alcohol
Glycerol
Salicylic acid
Ethylene glycol
K2Cr2O7
Concentrated H2SO4
KMnO4
FeCl3
NaNO2
NaOH
CuSO4
Formalin
AgNO3
NH3
HC2H3O2
HCl
Urea
Red litmus paper
Blue litmus paper
Test tubes
Test tube racks
Droppers
Labels
Markers
Procedure:
A. Tests for Hydroxyl Group
1. Chromic Acid Test: In separate test tubes, place 5 drops of the following compounds:
isopropyl alcohol, glycerol, and salicylic acid. Add 5 drops of K2Cr2O7 with shaking, and
note any change. Add concentrated H2SO4 drop wise with shaking, and note any change.
Disposal: A blue or green mixture may be disposed down the sink. An orange mixture may
be treated with ethanol until blue or green. Any other color must be thrown in the
nonhalogenated waste container.
2. Oxidation: In separate test tubes, place 5 drops each of the following compounds:
isopropyl alcohol, glycerol, ethylene glycol, and salicylic acid. Add 1 drop of KMnO4,
and shake the mixture. Note all color changes (some may have more than one, and it
might take some time before all color changes are seen).
Disposal: Dispose in the nonhalogenated waste beaker.
3. Ferric Chloride Test: In a test tube, add 5 drops of salicylic acid. Add 5 drops of FeCl3
with shaking, and note any changes.
Disposal: Dispose in the nonhalogenated waste beaker.
4. Modified Liebermann’s Test: In a test tube, place 5 drops of salicylic acid. Add 5 drops
of NaNO2 with shaking, and note any changes. Add concentrated H2SO4 drop wise with
shaking, and note any changes. Keep adding H2SO4 until no more change is occurring.
Pour into 20mL of cool tap water, and add 5 drops of NaOH solution. Note any changes,
and keep adding 5 drops of NaOH solution with shaking until the change is permanent.
Disposal: Dispose in the nonhalogenated waste beaker.
5. Schulze’s Test: In separate test tubes, place 5 drops of salicylic acid. Add 5 drops of
CuSO4 solution with shaking, and note the color.
Disposal: Dispose in the nonhalogenated waste beaker.
6. Thoms’ Test: In separate test tubes, place 5 drops of salicylic acid. Add 2 drops of
formalin with shaking, and add concentrated H2SO4 drop wise with shaking. Note any
change.
Disposal: Dispose in the nonhalogenated waste beaker.
B. Tests for Carbonyl Group
1. Tollens’ Test: In separate test tubes, place 10 drops of AgNO3 solution and a drop of
NaOH solution. Add NH3 solution drop wise until the black precipitate just dissolves, and
add a drop of formalin. Mix thoroughly, let stand for a few minutes, and note any change.

2. Disposal: Pour the contents into the Tollens waste beaker. Wash the test tube with dilute
HNO3 to dissolve the product, and pour into the waste beaker as well. Acidify the contents of
the beaker with dilute HNO3, and neutralize with Na2CO3. Precipitate Ag+ by adding
sufficient NaCl. Discard the precipitate in metals waste beaker and the liquid down the sink.
C. Tests for Carboxyl Group
1. Ferric Chloride Test
a. In separate test tubes, add 2 drops NaOH. Add HC2H3O2 drop wise until the solution is
slightly acidic to litmus. Add FeCl3 solution drop wise, and note any changes. Add HCl
drop wise, and note any changes.
b. In separate test tubes, add 5 drops of salicylic acid. Add NH3 drop wise until the solution
is slightly basic to litmus. Add 2 drops of FeCl3 solution, and note any changes. Add HCl
drop wise, and note any changes.
Disposal: Neutralize with acid or base, and dispose down the sink.
D. Tests for Amino Group
1. Sulfuric Acid Test: In a test tube, add a few crystals of urea. Add concentrated H2SO4
drop wise with shaking, and note any changes. Transfer some precipitate to a clean test
tube, and add 1mL of water. Note any changes.
Disposal: Dissolve the crystals with 25% NaOH. Discard the organic layer in the
nonhalogenated waste beaker. Neutralize the aqueous layer with H2SO4, dilute with water,
and dispose down the sink.
References:
1. Pharmaceutical Chemistry Department. 2011. Laboratory Manual in Pharmaceutical
Organic Chemistry I. University of the Philippines Manila, Manila, pp. 64-84.
2. Cohn AI. 1903. Tests and Reagents: Chemical and Microscopical. John Wiley & Sons,
Inc., Brooklyn, pp. 1-339.

3. Experiment Data Sheet
Name:
Date:
I. Tests for Hydroxyl Group
#1.
Color of initial solution Isopropyl alcohol Glycerol Salicylic acid
Color of initial
solution
----------------------------
+K2Cr2O7
+H2SO4
#2.
Color of initial
solution
Isopropyl
alcohol
Glycerol Ethylene
glycol
Salicylic acid
Color of initial
solution
+KMnO4
#4.
Color of initial solution +NaNO2 +H2SO4 +water +NaOH
Color of initial solution ----------------------------
Salicylic acid
#3, 5, 6.
Color of initial solution +FeCl3 +CuSO4 +formalin+H2SO4
Color of initial solution ----------------------------
Salicylic acid
II. Tests for Carbonyl Group
Color of original solution Formalin
Color of original solution -------------------------------
AgNO3 + NaOH + NH3
III. Tests for Carboxyl Group
Color of initial solution + FeCl3 + HCl
Color of initial solution ----------------------------
NaOH + HC2H3O2
Salicylic acid + NH3
IV. Tests for Amino Group
Color of initial solution +concentrated H2SO4 + water
Color of initial solution ----------------------------
Urea