Procedure for Experiment 7: “Organic Functional Groups”
Safety
 Be extra careful about wearing gloves and eye protection and using the hoods. Avoid skin
contact for all reagents, many of which contain sulfuric acid or nitric acid which will “eat up”
your clothes and books as well as burn your skin. Be sure to avoid open flames and do all
heating in a water bath or a hot plate.
 Be sure all waste goes into the appropriate waste container. Under no circumstances is waste
to be poured down the sink; although it is acceptable to wash the glassware in the sink after
you have removed the contents.
 Under no circumstances should you put a used pipette directly into any reagent container!
General Instructions: (HANDWRITE THIS PART INTO YOUR NB FOR PROCEDURE!!!)
Glassware, etc. needed: test tubes, test tube rack, Pasteur pipettes and bulbs
1.
Record your unknown number in your notebook along with the physical appearance and odor
of your Unknown. (Caution: Never put your nose directly near an organic compound and
inhale. The proper procedure for smelling an organic compound requires you to hold it in front
of you at nose level and then use one hand to waft the air toward you. If you cannot smell the
compound , you may move it a little closer. Be very careful!!)
2.
Beginning with one reagent, test the functional group standards and the unknown before
moving to the next reagent.
3.
Observe any evidence of physical change (e.g. color change, bubbles, precipitate, etc.) and
record those observations in the box which matches the functional group and the reagent you
have used. Record results for the unknown also. Be sure to mix the solutions well before
describing the results. Carefully DESCRIBE the results of the test so that you can use them
for future reference. Remember, a simple “it reacted” will NOT suffice!!!
*****DO NOT WASTE REAGENTS********
(YOU MAY PRINT AND TAPE THE FOLLOWING INTO YOUR NB FOR PROCEDURE)
1. Ceric ammonium nitrate test -1. Put 1-2 mL of ceric ammonium nitrate in a clean test tube.
2. Add one drop of the organic compound to be tested.
3. Agitate the tube thoroughly and record your observations.
2. Chromic acid or Chromic Anhydride tests –
1. Put 1-2 mL of the substance to be tested in a clean test tube.
2. Add one drop of chromic acid reagent.
3. Agitate the tube thoroughly and record your observations.
3. Zinc Chloride in HCl (a.k.a Lucas Test) -1. Put about 3 mL of the zinc chloride in HCl solution in a clean test tube.
2. Add 1 mL of the organic compound to be tested and stopper the
tube, if possible.
3. If no visible change is observed, set the tube aside and check it again
in 2 minutes and in 5-10 minutes.
4. Record all results, including the time it takes for reaction to occur.
4. Tollen’s Test -Tollen’s reagent does not have a long shelf life and must be prepared immediately before
using it. We may have to make our own on the day of lab. If so, here is the procedure.
1. Put 2 ml of the silver nitrate solution provided into a clean test tube.
2. Add 1-2 drops of dilute KOH or NaOH solution.
3. While avoiding a large excess of ammonium hydroxide, add dilute
ammonium hydroxide dropwise with shaking until the precipitate which
forms just dissolves. (The solution may be light brown but should not
have white precipitate.) Now you have prepared the Tollen’s reagent.
1. Add one drop of your unknown and agitate the solution.
2. Observe and record your results.
5. 2,4-Dinitrophenylhydrazine test -1. Put 1-2 mL of the 2,4-dinitrophenylhydrazine reagent in a clean test tube.
2. Add one drop of the organic compound to be tested.
3. Record your observations
6. Bromination tests -1. Put 1-2 mL of the bromine water solution in a clean test tube.
2. While holding a wet piece of blue litmus paper near the mouth of the
tube (don’t get any bromine on the strip), add 1-2 drops of the organic
compound to be test tube.
3. Agitate the tube thoroughly and record your observations.
1. Put one to two mls of the bromine in CH2Cl2 solution in a clean test tube.
2. While holding a wet piece of blue litmus paper near the mouth of the
tube (don’t get any bromine on the strip), add 1-2 drops of the organic
compound to be test tube.
3. Agitate the tube thoroughly and record your observations.
7. Ferric Chloride test -1. Put 1-2 mLs of ferric chloride solution in a clean test tube.
2. Add one drop of the organic compound to be tested.
3. Agitate the tube thoroughly and record your observations.