EXPERIMENT 13

PROCEDURES

1. Chromic Acid test

1. Prepare three test tubes, put 20 drops of n-butyl alcohol on the 1st test tube, sec-butyl alcohol on the 2nd and tert-butyl alcohol on the 3rd, LABEL each test tube accordingly.

2. Put 10 drops of 5% potassium dichromate and 10 drops of 5% sulfuric acid on each of the test tubes.

3. Prepare a boiling water bath, and put the test tubes. Prepare a timer and record the time as each of the test tubes change color. Also record the color and odor of each of the solutions.

2. LUCAS TEST

• Prepare four test tubes, put 20 drops of tert-butyl alcohol on the 1st , sec-butyl alcohol on the 2nd, n-butyl alcohol on the 3rd, and benzyl alcohol on the 3rd.

• Add 20 drops of freshly made LUCAS REAGENT on each of the test tubes. Shake once and let it rest.

• Prepare the timer, and record the time as the insoluble layer (emulsion) forms on each of the test tube, tis indicates the production of alkyl halide.

Alcohol

Alcohols are compounds containing the hydroxyl (-OH) functional group bonded to an alkyl, R and thus may be represented by the general formula ROH.

Reactivity is mainly attributed to the -OH group.

Has an inherent acid character shown when the hydrogen is released from the -OH bond.

May also be protonated at the oxygen, which weakens the C-O bond so that the whole group may be cleaved off as water and subsequently replaced in the molecule

Procedure 3Materials needed: Test tube and dropperChemicals needed: Methanol Salicylic acid Concentrated sulfuric acid

Steps:1. Put 20 drops of Methanol in a dry test tube2. Add 10 drops of Salicylic acid

3. Add 5 drops of Concentrated sulfuric acid

p.s: Observed the odor and time for the odor to develop

ESTERIFICATION

4. Methyl alcohol

(Reaction with Copper)

• 10 drops of Methyl alcohol with 10 drops of Distilled water mixed in a vial.

• Heat a Copper spiral over a Bunsen flame, then dip it to the methyl alcohol-water mixture. Repeat this step 20-25 times.

• Carefully add 1 drop of 0.5% resorcinol and 10 drops of concentrated sulfuric acid.

*do not shake

P.S.: note the color change produced at the junction of the two layers

5. Iodoform Test

• Iodoform is the organ iodine compound with the formula CHI3. A pale yellow, crystalline, volatile substance, it has a penetrating odor (in older chemistry texts, the smell is sometimes referred to as the smell of hospitals) and, analogous to chloroform, sweetish taste. It is occasionally used as a disenfectant.

a. To 4 drops of ethyl alcohol, add 4 ml of iodine solution. Then add drop by drop 10% NaOH until the iodine is decolorized.

b. Place the test tube in a warm bath (60◦c).

c. Repeat the test with: 1. isopropyl alcohol, 2. methyl alcohol in place of ethyl alcohol.

Test for Glycerol

A. Solubility in water and ether

1. Add 3 mL of water/ether in small portions, to the test compound in a dry test tube.

2. Shake vigorously after each portion is added.3. From the addition of the first portion, record

the time required for the solute to dissolve.4. Determine whether the sample is soluble,

slightly soluble or insoluble based on recorded time.

B. Acrolein Test

• Place two drops of glycerol in a dry test tube and add a pinch of KHSO4. Heat the test tube over the flame. Note the odor produced.

What is Esterification??Esters are derived from carboxylic acids. A carboxylic acid contains the -COOH group, and in an ester the hydrogen in this group is replaced by a hydrocarbon group of some kind. We shall just be looking at cases where it is replaced by an alkyl group, but it could equally well be an aryl group (one based on a benzene ring). Esters have a very sweet fruity smell. Naturally occurring esters are found in fruits.

When salicylic acid reacts with methanol , Methyl salicylate is formed. C6H4(OH)COOCH3 or C8H8O3

Procedure 7Material needed: Cork with U-shaped glass tubing 2x Erlenmeyer Flask Test tube Beaker Bunsen burner Ice Yeast Pineapple Chunks

Chemicals needed: Lime water 5% Potassium dichromate 5% Sulfuric acid

FermentationSteps: 1.Slice an overripe pineapple into chunks (without skin). And then blend them. 2. Filter out the juice. 3. Measure the volume of the juice obtained and add 5 grams of Baker's yeast for every 500 mL of the juice. Mix thoroughly. 4. Set up your apparatus as shown on the left image.

5. Place the mixture in the Erlenmeyer flask. 6. Then place some lime water in a test tube. 7. Set aside for 5 days.

8. Carefully separate the liquid in the flask after decanting it for 5 days.9.Transfer the obtained liquid to a a new erlenmeyer flask and then add 2-3 pieces of boiling chips.

10. Collect the distillate when the temperature reaches 78-79 °C11.Test the distillate for the presence of alcohol using flammability test and chromic acid test.

Extra Info about Fermentation

The overall process of fermentation is to convert glucose sugar (C6H12O6) to alcohol (CH3CH2OH) and carbon dioxide gas (CO2). The reactions within the yeast cell which make this happen are very complex but the overall process is as follows:

C6H12O6 ====> 2(CH3CH2OH) + 2(CO2) + Energy (which is stored in ATP) Sugar ====> Alcohol + Carbon dioxide gas + Energy(Glucose) (Ethyl alcohol)