laporan destilasi fraksinasi
TRANSCRIPT
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