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Many carbon compounds find applications in almost all aspects of our daily life as we have seen earlier. In this chapter two very important organic compounds ethanol and ethanoic acid are discussed.
Usually the term 'alcohol' refers to ethanol. Man has been using ethanol for thousands of years especially in the form of wine.
The structural formula of ethanol is given as follows:
Its molecular formula is CH3CH2OH or C2H5OH
- Ethanol is colourless liquid and has a pleasant odour.
- Its boiling point is 78o C and its freezing point is -114oC.
- It is soluble in water and almost all the organic solvents.
- It is highly intoxicating in nature.
- It is combustible and burns with a blue flame.
Action with Sodium Metal
When a piece of sodium is dropped in ethyl alcohol, bubbles of hydrogen gas are observed.
Action with Phosphorus Trichloride
Ethanol reacts with phosphorus trichloride to form ethyl chloride.
Action with Concentrated Sulphuric Acid
At 170oC ethyl alcohol undergoes dehydration when treated with concentrated H2SO4 to form ethane.
At lower temperature of 140oC and when present in excess ethyl alcohol forms a pleasant smelling substance called diethyl ether.
Oxidation of Ethyl Alcohol by Acidified Potassium Dichromate
Alcohols on oxidation give aldehydes. The aldehydes on further oxidation give carboxylic acids.
All these are important chemical compounds used further by chemical industries.
- Ethyl Alcohol is used as a solvent for many organic solutes, especially which are insoluble in water.
- It is used in the preparation of perfumes.
- It is used in the manufacturing of gasohol, which is 90% mixture of petrol (gasoline) and 10% ethanol. It helps to save gasoline.
- Ethyl Alcohol is used in making tinctures and medical syrups.
- It is used in alcoholic beverages.
- It is used as a solvent for paints, varnishes, dyes etc.
- It is used in the production of many organic compounds.
Chemically the term alcohol refers to a group of organic compounds, having
-OH group in their composition. But the word alcohol used by the common man refers to ethyl alcohol or ethanol. It has a variety of uses, especially as a solvent. But by far the greatest use of alcohol is in the form of alcoholic beverages, such as wine, beer, rum, brandy, whisky etc. In small quantities it may serve as a source of energy, but in large amounts, it affects the nervous system. The person experiences loss of control over muscles and loses his or her sense of balance and mental ability. It can be a habit forming activity. If consumed over a period of time, alcohol can ruin one's health especially the liver, which gets affected by cirrhosis. This type of consumption can be fatal and ruins one's family life.
Alcoholic drinks are heavily taxed by the government, so as to discourage people from over consuming it. Alcohol used for industrial and surgical purposes is not taxed heavily. But in order to prevent people form buying and consuming this alcohol, it is mandatory that ethyl alcohol be mixed with a certain percentage of highly poisonous methyl alcohol or methanol. This renders the ethyl alcohol unfit for human consumption. This mixture is called "Methylated Spirit". If chemicals like copper sulphate or pyridine are added to ethyl alcohol it is called 'denatured alcohol'.
| Denatured spirit or methylated spirit mixture is prepared so as to prevent people from drinking ethanol heavily.
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This is illicit liquor made by improper distillation or by using methylated spirit. It is cheap and is mostly used by the lower strata of our society. It contains higher percentage of methyl alcohol, which is poisonous. Consumption of such liquor may cause blindness, other serious health problems and even death. Sometimes even other chemicals are mixed with the ethyl alcohol so that the consumer gets a feeling of "intoxication". Even these are highly poisonous and can cause severe damages to the body and even death can occur.
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