DETERMINATION OF ALCOHOL IN COSSACK VODKA BY MEANS OF SIMPLE DISTILLATION
ABSTRACT:

Cossack Vodka is distilled liquor composed primarily of water and ethyl alcohol or ethanol (CH3CH2OH) without a definite aroma or taste. Alcohol is a primary content of vodka, and distillation – a process involving condensation and evaporation wherein solvents of different boiling points are separated from each other – is a method that may be used to determine the certain presence of Alcohol content in Cossack vodka. A certain number (17) of test tubes were obtained, each with 0.05 ml until the temperature reached 93(C. The volume of distillate collected by the end of the experiment was 9.00 ml at 93(C, giving percent ethanol of 30.00 %.

I. INTRODUCTION: Distillation is the process of evaporating a volatile substance from a solution of non-volatile substance wherein the vapor afterwards is condensed in the condenser and collected in the receiving flask. Simple distillation is a process of separating two liquids with different boiling points. It can be used to separate liquids with boiling points of at least fifty degree Celsius. There are four types of distillation: simple, fractional, vacuum, and azeotropic. Vodka is a colorless liquid made by distilling fermented substances such as sorghum, corn, rye or wheat. Vodka is said to contain 40% to 55% alcohol. The experiment aims to: (a) separate the components of Vodka, an alcoholic beverage, by the means of distillation, particularly simple distillation, (b) compute for the percent ethanol and percentage loss in alcohol (Vodka)

II. METHODOLOGY

A. Simple distillation A simple distillation set-up was prepared, with a distilling flask connected with the distilling adapter, and a mercurial thermometer attached at its tip to monitor the temperature of the vapor. It is as well connected to the condenser glassware, to the receiving adapter, and a test tube calibrated by 5 drops as a receiving flask. Rubber tubes were attached at the water in and water out outlet of the condenser. Prior to the experiment the set-up was checked for safety and effectiveness purpose. A certain amount (20 ml) of vodka sample was calculated using a graduated cylinder then poured to the distilling flask after setting in boiling chips into the glassware - boiling chips are used to create smooth boiling procedure. After arranging the glassware the alcohol lamp, which acted as a source of heat, was flamed then distillation started. A certain number (17) of test tubes were obtained, each with 0.05 ml until the temperature reached 93(C.

B. Flammability Test The flammability test was completed with the first and last distillate. The first distillate was poured onto an evaporating dish then lighted with a match, eliciting a blue flame at contact with the substance.

C. Determination of % ethanol
% ethanol = Vol. of distillate x100 Vol. of sample = 9 ml x100 30 ml % ethanol = 30.00 %

III. RESULTS & DISCUSSION In the experiment, quick-fit instrument are used, such apparatus are the following: (a) the pear-shaped distilling flask in which contained the sample, (b) still head that supports the thermometer to allow quick flow of vapor-temperature-measurement during the experiment, (c) condenser, a tube surrounded by water jacket for water inlet and outlet, (d) thermometer that measures the current temperature, (e) receiver adapter that connects the condenser to the receiving flask, and (f) test tubes that was used as receiving flask where the distillate was collected. Refer to Fig. 1

Fig, 1. Simple Distillation set-up

Boiling chips were contained in the pear-shaped flask accordingly for a production of a smooth boiling procedure. Boiling chips have pores and traps air in which they provide spaces where bubbles can form. These bubbles ensure even boiling and prevent bumping and over-boiling and loss of substance.

The flask should be heated in a slow rotation. If heating was made too abrupt equilibrium between liquid and vapor will not occur and the separation of components would not be successful. If the distilling flask is heated strongly even before the distilling adapter or still head had been warmed the still head may flood or show excessive amount of liquid.

The following table shows the result from the simple distillation:
|Test Tube |Volume (ml) |Temp. ((C) |Flame Test |
|1 |0.50 |78 |Flame(Blue) |
|2 |1.00 |79 | |
|3 |1.50 |80 | |
|4 |2.00 |81 | |
|5 |2.50 |82 | |
|6 |3.00 |82 | |

Table 1. Volume, Temperature, Flammability test of distillate

Table 1 shows that as the volume of distillate increases, the temperature increases until the point of the temperature reached 93(C. In the experiment two distinct distillates were obtained - the first distillate and the last distillate.

Dalton's Law of Partial Pressure explains that the total pressure is equal to the sum of all of the pressures of the parts. And Raoult’s Law states that when two substances whose molecules are very similar form a liquid solution, the vapor pressure of the mixture is very simply related to the vapor pressures of the pure substances.

In the flammability test the first test tube elicited a fire. The flame concluded the presence of alcohol that is capable of eliciting flame when in contact with fire. The last distillate (19th), when completed with the flammability test, failed to elicit a flame. It illustrated the absence of ethanol (CH3CH2OH) in the substance and the dominancy of water – that is incapable of flaming up when in contact with fire.

|7 |3.50 |82 | |
|8 |4.00 |81 | |
|9 |4.50 |82 | |
|10 |5.00 |83 | |
|11 |5.50 |84 | |
|12 |6.00 |87 | |
|13 |6.50 |84 | |
|14 |7.00 |84 | |
|15 |7.50 |89 | |
|16 |8.00 |91 | |
|17 |8.50 |92 | |
|18 |9.00 |93 |No flame |

Fig. 2 Temperature as a Function of volume

Figure 2 shows that as the volume increases, the temperature also increases. After performing the tests the percent ethanol and percent loss can be computed.

% ethanol = Vol. of distillate x100 Vol. of sample = 9 ml x100 30 ml % ethanol = 30 %

% loss = vol. of sample –
(vol. of residue + total vol. of distillate) x100 Vol. of sample = 30 ml – (7+9) x100 30

REFERENCES

http://en.wikipedia.org/wiki/Vodka#Production (n.d.) retrieved June 30, 2012

http://www.britannica.com/EBchecked/topic/631781/vodka retrieved June 30, 2012

http://www.thefreedictionary.com/distillation (n.d.) retrieved July 3, 2012

http://orgchem.colorado.edu/Technique/Procedures/Distillation/Boilingchips.html (n.d.) retrieved July 3, 2012

http://www.rod.beavon.clara.net/distil.htm (n.d.) retrieved July 3, 2012

http://www.ehow.com/list_6924000_types-distillation.html (n.d.) retrieved July 3, 2012

http://library.thinkquest.org/12596/dalton.html (n.d.) retrieved July 3, 2012

-----------------------
[pic]