/23 TI /21 C /6 A
Name:
/50 MARKS
Background:
The reactivity of alcohols can be accounted for by their molecular structure – particularly by the attachment of their hydroxyl functional group. The isomers of butanol are used as examples of 1°,2° and 3° alcohols to examine this relationship. Each of the three isomers of butanol will be mixed with concentrated hydrochloric acid. The presence of an alkyl halide product is indicated by cloudiness of the mixture, as the halides are only slightly soluble in water. This test indicates that a halogenation reaction has taken place. Each alcohol is also separately mixed with dilute potassium permanganate solution, which …show more content…
Avoid contact with skin, eyes, clothing, and lab bench. Work in the fume hood.
All three alcohols are highly flammable. Do not use near an open …show more content…
Place 3 test tubes in a test tube rack. Using a clean eye dropper for each alcohol, place 2 drops of butan-1-ol in the first tube, in the second place 2 drops of butan-2-ol, and in the third place 2 drops of 2-methylpropan-2-ol.
2. Carry the test tube rack to the fume food, and use a clean dropper to add 10 drops of concentrated HCl to each of the three test tubes. Shake the mixture very gently and carefully. Return to your lab bench with the test tube rack.
3. Allow the tubes to stand for 1 minute and observe for evidence of cloudiness. Also note the time it takes for any to turn cloudy within the minute.
4. Dispose contents according to Mrs. McAdam’s instructions.
5. Set up the 3 more test tubes as in step 1, but use 4 drops of each alcohol.
6. To each tube, carefully add 2 mL of the KMnO4 solution. Shake the mixture carefully.
7. Allow the tubes to stand for 5 minutes, with occasional shaking. Observe and record any colour change to the solution in each tube, and the time it takes for any to change colour within the 5 minutes.
8. Dispose contents according to Mrs. McAdam’s instructions.
Observations: (12 marks – C)
Alcohol
HCl added
KMnO4 added