INTRODUCTION Aliphatic hydrocarbons with 1 double bond between carbons are called alkene. They follow the naming convention of the alkanes except that the suffix -ene is used instead of -ane. From alkene, we can produce alcohol by hydration of alkene. Hydration is a process of adding water directly to the carbon-carbon double bond (C=C). The objective of the experiment is to get the alcohol from the alkene through hydration reaction and to differentiate the physical properties between the alkene and the alcohol. APPARATUS 1 . Goggles 2. Disposable nitrile gloves 3. Beaker (250ml) 4.
Measuring cylinder (5ml or 10ml) – 2 5. Boiling tubes -2 6. Glass stirring rod CHEMICALS 1. Ice , a few lumps 2. Hex-I-ene (IRRINTANT ,HIGHLY FLAMMABLE) 3. 75% sulphunc acid (CORROSIVE) – 1 5ml 4. Distilled water – 20ml For distillation 1 . Anhydrous sodium carbonate (IRRITANT) – 0. 5g 2. Bromine water, 0. 01 M (HARMFUL at this concentration) – Iml 3. Acidified potassium manganate (VI’) solution ,about 0. 001M – Iml 4. Sodium (HIGH FLAMMABLE,CORROSIVE) – a small piece no bigger than 2mm 5. Eye protection 6. Beaker (250 rnl) 7. Separating funnel (250ml) 8. Conical flask (250ml) 9.
Filter funnel 10. Filter paper 11. Distillation apparatus,with thermometer (0-200 or 0-250 ) 12. Test-tube rack 13. Test-tubes , with corks – 8 14. Forceps 15. Scalpel PROCEDURES PREPARING THE MIXTURE 1. A few lumps of ice and some water was placed in a beaker to make an ice bath. 2. 15 ml of hex-I-ene was measured using a measuring cylinder it was poured into a boiling tube. 3. The hex-I-ene was allowed to cool in the ice bath for about three cylinder. 5. An acid was added to the hex-I-ene slowly while keeping the tube in the ice bath and the mixture was stirred using a glass rod. 6.
The mixture was stirred continuously when all the acid has been added until it becomes homogeneous. It took about 5 minutes. 7. The mixture was allowed to stand in the ice bath for another 5 minutes, then an equal volume of cold water was carefully added by using another boiling tube. The mixture separated in two layers. The top layer was impure hexan-2- 01, the lower layer contained mainly sulfuric acid. DISTILLATION OF THE PRODUCT 1. The contents in the boiling tube was tipped into a beaker. Then the contents was poured into a separating funnel, stopper, shake and the contents was allowed to ettle. . The stopper was removed and the lower layer were ran off into a beaker and it was discarded by carefully washed it down the sink with plenty of water. 3. 20 ml of distilled water was added to the separating funnel, stopper and shake. This washed the hexan-2-ol. The stopper was removed and the bottom aqueous layer was ran off then it was discarded. 4. 0. 5 g of anhydrous sodium carbonate was placed in a 250 ml conical flask. The hexan-2-ol was ran out of the separating funnel into the flask. The flask then was swirled frequently for about twenty minutes until the hexan-2-ol dried. The distillation apparatus was set up. The hexan-2-ol was unloaded as much as possible from the conical flask into the distilling flask and then the rest was filtered into the distilling flask. 6. Distilled. The hexan-2-ol was collected at 1300 and 1600C. Hex-I-ene boiled at much lower temperature, 630C. 7. A few drops of hex-I-ene and hexan-2-ol were used for each test to compare them. RESULTS Hex-I -ene Test reactions Hexa-2-nol Heterogenous is formed (top layer-colorless, bottom layer-yellow color) Bromine water, (Br2) Brown color change to colorless Purple color change to pale yellow
Potassium manganate,(KMn04) Purple color change to dark brown No reaction Sodium metal , (Na) More soot Lit splint Less soot DISCUSSION From the experiment, we found that alcohol is produced from the hydration of alkene. Electrophilic addition is a reaction in which two molecules Join together to make a bigger one. Nothing is losing in the process. The overall preparation is: C6H12 *H20 C6H130H The alkyl hydrogensulfate reacts with water to give alcohol and regenerates sulfuric acid. The secondary alcohol hexan-2-ol is formed rather than the primary hexan-l-ol.