I. TITLE OF EXPERIMENT : FRACTIONATION DISTILLATION

II. OBJECTIVE :

Determine the refractive index of distillate

determine the percentage purity of the distillate

III. BASIC THEORY

SPIRIT SOLUTION

Spirit solution is the alcohol solution in the water (the content of alcohol is

about 85%). This solution is adding something which is poison like methanol, in order

it can make for liquor. Spirit solution is the others name of methanol. And it has the

formula CH3OH.

Alcohol made from sugar solutions by fermentation and distillation. Alcohol is

sharing of the degree of purity. At first the manufacture of spirits is meant to create

a variety of average (alcohol content is 19-50%) and spirits needed a much higher

alcohol content (70-96%) so it is no longer for the liquor industry.

FRACTIONAL DESTILLATION

Fractional distillation is the

separation of a mixture into its component

parts, or fractions, such as in separating

chemical compounds by their boiling point

by heating them to a temperature at which

several fractions of the compound will

evaporate. It is a special type of distillation.

Generally the component parts boil at less

than 25 °C from each other under a

pressure of one atmosphere (atm). If the difference in boiling points is greater than

25 °C, a simple distillation is used.

Fractional distillation in a laboratory makes use of common laboratory

glassware and apparatuses, typically including a Bunsen burner, a round-bottomed

flask and a condenser, as well as the single-purpose fractionating column.

Fractional distillation apparatus using a Liebig condenser. A conical flask is

used as a receiving flask. Here the distillation head and fractionating column are

combined in one piece.

heat source, such as a hot plate with a bath, and ideally with a magnetic

stirrer.

distilling flask, typically a round-bottom flask

receiving flask, often also a round-bottom flask

fractionating column

distillation head

thermometer and adapter if needed

condenser, such as a Liebig condenser, Graham condenser or all in condenser

vacuum adapter (not used in image to the right)

boiling chips, also known as anti-bumping granules

Standard laboratory glassware with ground glass joints, e.g. quick fit

apparatus.

METHANOL

Methanol, also known as methyl alcohol, wood

alcohol, wood naphtha or wood spirits, is a chemical with

formula C H 3O H . It is the simplest alcohol, and is a light,

volatile, colorless, flammable, liquid with a distinctive odor

that is very similar to but slightly sweeter than ethanol (drinking alcohol).[4] At room

temperature it is a polar liquid and is used as an antifreeze, solvent, fuel, and as a

denaturant for ethanol. It is also used for producing biodiesel via trans esterification

reaction.

Methanol is produced naturally in the anaerobic metabolism of many

varieties of bacteria, and is ubiquitous in the environment. As a result, there is a

small fraction of methanol vapor in the atmosphere. Over the course of several days,

atmospheric methanol is oxidized with the help of sunlight to carbon dioxide and

water.

Methanol burns in air forming carbon dioxide and water:

2 CH3OH + 3 O2 → 2 CO2 + 4 H2O

A methanol flame is almost colorless in bright sunlight.

Because of its toxic properties, methanol is frequently used as a denaturant

additive for ethanol manufactured for industrial uses — this addition of methanol

exempts industrial ethanol from liquor excise taxation. Methanol is often called

wood alcohol because it was once produced chiefly as a byproduct of the destructive

distillation of wood.

The boiling point of methanol is 65 °C, 338 K, 149 °F and the appearance is

colorless liquid.

ETHANOL

Ethanol, also called ethyl alcohol, pure alcohol, grain

alcohol, or drinking alcohol, is a volatile, flammable, colorless

liquid. It is a powerful psychoactive drug and one of the oldest

recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it

is also used in thermometers, as a solvent, and as an alcohol fuel. In common usage,

it is often referred to simply as alcohol or spirits.

Ethanol is a straight-chain alcohol, and its molecular formula is C2H5OH. Its

empirical formula is C2H6O. An alternative notation is CH3–CH2–OH, which indicates

that the carbon of a methyl group (CH3–) is attached to the carbon of a methylene

group (–CH2–), which is attached to the oxygen of a hydroxyl group (–OH). It is a

constitutional isomer of dimethyl ether. Ethanol is often abbreviated as EtOH, using

the common organic chemistry notation of representing the ethyl group (C2H5) with

Et.

The fermentation of sugar into ethanol is one of the earliest organic reactions

employed by humanity. The intoxicating effects of ethanol consumption have been

known since ancient times. In modern times, ethanol intended for industrial use is

also produced from by-products of petroleum refining.[3]

Ethanol has widespread use as a solvent of substances intended for human

contact or consumption, including scents, flavorings, colorings, and medicines. In

chemistry, it is both an essential solvent and a feedstock for the synthesis of other

products. It has a long history as a fuel for heat and light, and more recently as a fuel

for internal combustion engines. The Boiling point of ethanol is 78 °C, 351 K, 172 °F.

IV. CHEMICALS & EQUIPMENTS :

Tools

Tools Amount

Distilling flask 1

Condenser 1

Test tube 4

Drops Pipette 3

Beaker glass (500mL) 1

Measuring glass (10mL) 1

Stative 2

Beaker glass (50mL) 1

Tissue 1

Thermometer 1

Rack 1

Boiling stones 2

Electric heating 1

Hose 2

Isolation 1

Clamp 2

100 mL of spirit solution

Distillate

Purity Distillate

Entered into distillationHeated until maximum temperature 64.5 OC

Residue

Placed into beaker glassTook at every 10 mL that producesFound the refraction indexCompared with refraction index of methanol 99.9%, 95%, 80%, 70%, 60%, 50%, 40%, 30%

Material

- Spirit solution (100mL)

- Methanol 99.9%

- Methanol 95%

- Methanol 80%

- Methanol 70%

- Methanol 60%

- Methanol 50%

- Methanol 40%

- Methanol 30%

V. PROCEDURE

100 mL of spirit solution

Distillate

Purity Distillate

Entered into distillationHeated until maximum temperature 64.5 OC

Residue

Placed into beaker glassTook at every 10 mL that producesFound the refraction indexCompared with refraction index of methanol 99.9%, 95%, 80%, 70%, 60%, 50%, 40%, 30%

VI. OBSERVATION RESULT

Number Procedure of Experiment Observation Result Hypothesis /

Reaction

Conclusion

1. T1 (room

temperature) = 28.5 oC

T2 = 64.5 oC

The color of

distillates is colorless

The color of spirit

solution is purple

clear

Refraction index of

methanol :

30% = 1.337339

40% = 1.339441

50% = 1.341540

60% = 1.341540

70% = 1.340541

80% = 1.338341

95% = 1.334040

99,9% = 1.326042

Our distillate =

1.333041

The refractive

index of our

fractionation

distillation :

1st distillate is

1.333041

2nd distillate is

1.335242

3rd distillate is

1.335240

Purity

percentage of

our distillate :

1st distillate is

95.612%

2nd distillate is

71.317%

3rd distillate is

71.356%

Based on the data observation, through the calculation with use the formula so will get the

purity percentage of our distillate :

Distillate - Refractive index Purity percentage Distillate Color

1 1.333041 95.612% Colorless

2 1.335242 71.317% Colorless

3 1.335240 71.356% Colorless

Average 1.334507 79.428%

VII. ANALYSIS AND DISCUSSION

A. ANALYSIS

In this experiment , the solution that we distillate is spirtus with the composition are

water (boiling point = 100 oC), methanol (boiling point = 64.5 oC), and ethanol (boiling

point = 78.3 oC). this experiment is done with fill distilling flask with 100 mL spirtus and

heated till 64.5 oC. This temperature must be constant, because the distillate that we are

taken is methanol that have boiling point 64.5 oC. If the temperature is greater than 64.5 oC , we don’t use the distillate. Then, the distillate that resulted is collected in beaker

glass as many as 3 times each of that is 7 mL, each of that is looked for refractive index

using refractometer, so we get refractive index as big as:

a. 1st distillate : 1.333041

b. 2nd distillate : 1.335242

c. 3rd distillate : 1.335240

After that, we compare refractive index of our distillate with refractive index of

methanol 30%, 40%, 50%, 60%, 70%, 80%, 95%, 99.9%, each of that have been available

and we are looked for the refractive index each of that.

Methanol 30% : 1.337339

Methanol 40% : 1.339441

Methanol 50% : 1.341539

Methanol 60% : 1.341540

Methanol 70% : 1.340541

Methanol 80% : 1.338341

Methanol 95% : 1.334040

Methanol 99.9% : 1.326042

After we compare with our result ,we get that our 1st refractive index distillate is

between 95% - 99.9%, and 2nd refractive index distillate is between 30% - 95%, and 3rd

refractive index distillate is between 30% - 95%. So, we can calculate the %distillate

purity (Xd) using this formula :

Based on the formula above, the calculation are :

1st distillate

Refractive index of 1st distillate (z) = 1.333041

Refractive index of lower boundaries(y) = 1.326042

Refractive index of upper boundaries (x) = 1.334040

% upper boundaries = 95%

% lower boundaries = 99.9%

X d=Z−YX−Y

¿ [ 1.333041−1.3260421.334040−1.326042

(0.95−0.999)]+0.999

¿ [ (6.999×10−7 ) (−0.049 )7.998×10−3 ]+0.999

¿ [−3.42951×10−4

7.998×10−3 ]+0.999

¿ (−0.042879+0.999 )×100 %

¿95.61 %

So, the purity distillate is 95.612%

% destillate purity=[z-yx-y

(% upper boundaries- % lower boundaries )]+% lower boundaries

2nd distillate

Refractive index of 1st distillate (z) = 1.335242

Refractive index of lower boundaries(y) = 1.334040

Refractive index of upper boundaries (x) = 1.337339

% upper boundaries = 30%

% lower boundaries = 95%

X d=Z−YX−Y

¿ [ 1.335242−1.3340401.337339−1.334040

(0.30−0.95)]+0.95

¿ [ (1.202×10−3 ) (−0.65 )3.299×10−3 ]+0.95

¿ [−7.813×10−4

3.299×10−3 ]+0.95

¿ (−0.236829+0.95 )×100%

¿71.317 %

So, the purity distillate is 71.317%

3rd distillate

Refractive index of 1st distillate (z) = 1.335240

Refractive index of lower boundaries(y) = 1.334040

Refractive index of upper boundaries (x) = 1.337339

% upper boundaries = 30%

% lower boundaries = 95%

X d=Z−YX−Y

¿ [ 1.335240−1.3340401.337339−1.334040

(0.30−0.95)]+0.95

¿ [ (1.2×10−3 ) (−0.65 )3.299×10−3 ]+0.95

¿ [ −7.8×10−4

3.299×10−3 ]+0.95

¿ (−0.236435+0.95 )×100%

¿71.356 %

So, the purity distillate is 71.356%

B. DISCUSSION

Based on our experiment, we found the difficulties in seeing each refractive index

of methanol 30%, 40%, 50%, 60%, 70%, 80%, 95%, 99.9%, in determining the point of

accurately of refractometer, so it affect in result of % distillate purity. Because each

student has a different assessment in determining the refractive index using a

refractometer. Perhaps the use of the refractometer is expected to have a special skill

before.

VIII. CONCLUSION

From the experiment above, we can conclude that :

1. The refractive index of our fractionation distillation of our spirtus are :

a. 1st distillate : 1.33041

b. 2nd distillate : 1.335242

c. 3rd distillate : 1.335240

2. The purity percentage of our fractionation distillation of our spirtus are :

a. 1st distillate : 96.39 %

b. 2nd distillate : 71.317 %

c. 3rd distillate :71.356 %

3. So it can be concluded that if higher of refractive index, thus lower the percent

purity. This is appropriate with the theory that the relationship between refractive

index and percent purity is inversely proportional, that if higher of refractive index,

so the percent purity is lower

ATTACHMENT

No. Picture Information

1.

Set of fractionation distillation

2.

Set of fractionation distillation

3.

Set of fractionation distillation

4.

Beaker Glass. To collect the distillate

5.

Refractometer

6. Our distillate

7. Methanol 30%, 40%, 50%, 60%

8. Methanol 70%, 80%, 95%, 99.9%

BIBLIOGRAPHY

Soebagio, Budiasih Endang dkk. 2003. Kimia Anlitik II JICA. Malang: Universitas Negri Malang

Tim penyusun: 2007. Panduan Praktikum Mata Kuliah Kimia Analitik II: Dasar-dasar

Pemisahan Kimia. Surabaya: Unipress Universitas Negeri Surabaya.

http://en.wikipedia.org/wiki/Methanol access in Sunday 25 March, 2012 at 6.30 pm