4. Ethyl alcohol and its types
In chemistry, any material which contains a hydroxyl agent (OH) in its chemical formula is considered as alcohol. Alcohols are derived from hydrocarbons and each molecule includes some hydrogen and carbon atoms. Then, each hydrogen atom is replaced by an OH agent. Valence of alcohol is determined based on the number of OH agents.
Ethylic alcohol or ethanol is a mono-valence type I alcohol. Ethanol which is also called white alcohol is a clear, fugacious, flammable liquid with specific odor. When mixed with water regardless of the amount, it burns easily and carbonic gas and water are resulted from its burn. Also, it evaporates fast and does not trace inappropriate environmental effects.
Under standard pressure, ethyl alcohol boils at 78.5°C and freezes at -117°C. The chemical formula of ethanol is C2H5OH and it is naturally found in bread and plants in small proportions. In addition to ferment and other bacteria, human body produces a considerable amount of alcohol and in most cases, it is concerned with microbes in intestine.
Ethyl alcohol burns like other organic materials and CO2 and water result from its burn. Since ethyl alcohol usually burns completely, no smog is produced; therefore, it can be used as the fuel for vehicles.
There are three kinds of ethyl alcohol in the market which are described below:
1. Medical ethylic alcohol
Medical ethylic alcohol (C2H5OH) with 46.07 molecular weight is a clear, colorless liquid which has a special, loud smell when mixed with water. It boils at 73.8°C and freezes at -117°C under normal conditions. It contains 96 volume percentage of C2H5OH and its specific weight in 20°C is maximum 0.8020. Ethanol burns easily with a blue flame and water and carbonic gas is remained.
2. Pure/Absolute ethylic alcohol
It is a colorless, clear, fugacious liquid which absorbs moisture and possesses a special odor. This kind of alcohol can be mixed with water, ether and chloroform. Absolute alcohol includes over 99.4 volume percentage of C2H5OH. It is flammable and burns with a blue flame. The specific weight of it in 20°C is 0.7940-0.7935. This type is also called waterless alcohol.
3. Inverted Alcohol
It is in fact the ethylic alcohol with permitted inverting additives which make it lose the purity and therefore lose its edible quality.
Inverted alcohol is of two kinds:
Type I: This type is actually the completely inverted ethylic alcohol whose minimum alcohol degree is 90 after inversion. It is used as fuel, alcohol lac and also is used in other industries.
Type II: This type is the ethylic alcohol which is inverted specifically. Its minimum alcohol degree is 96 after inversion and is used in cosmetics and pharmaceuticals.
In order to avoid alcohol drinking, it is inverted.
4. Medical 70/80-degree alcohol
In some countries, customs duties of alcohol import are defined according to its degree that is the lower the purity degree of alcohol; the less customs duties will be assigned. In European countries, 70/80-degree alcohol is more favorably used for medical uses. Therefore, one of the categories of alcohol is 70/80-degree alcohol.
Recently, in Iran, 70-degree alcohol in 100 and 120cc bottles has entered the market. The reason is the same antiseptic quality of the mentioned alcohol with the 96-degree one. However, 70-degree alcohol is cheaper.
