Ethanol (C 2 H 5 OH):
It is the second member of the homologous series of the alcohol family and comes after methanol.
The common name of ethanol is ethyl alcohol .
a. Physical Properties:
- It is a colorless liquid having a pleasant smell.
- The boiling point of ethanol is 78 o C . Since it has a low melting point, it is volatile in nature.
- Ethanol is a neutral compound and is completely soluble in wate r.
b. Chemical Properties:
Ethanol catches fire very easily and starts burning. Therefore, it is highly inflammable . On combustion, it produces carbon dioxide , water and energy in the form of heat and light . The reaction is given below:
Oxidation refers to controlled combustion . In this, ethanol is oxidized (i.e. oxygen is added to it) to form ethanoic acid with the help of alkaline potassium permanganate which acts as an oxidizing agent.
Reaction with sodium metal:
Ethanol reacts with sodium metal to form sodium ethoxide and hydrogen gas is released.
Dehydration Reaction :
Dehydration refers to the removal of water . In this reaction ethanol is treated with excess of concentrated sulphuric acid and leads to the formation of ethene that is an unsaturated hydrocarbon.
Uses of Ethanol:
- It is used as an antiseptic to sterilize wounds and equipments.
- Since it is inflammable , it is used as fuel along with petrol.
- It acts as a solvent i n various industries and is used in the manufacture of paints, perfumes etc.
Why is drinking Alcohol harmful?
- If a person consumes large quantities of ethanol, all the metabolic processes slow down and they also depress the central nervous system .
- Due to this, there is drowsiness, stupor, lack of coordination etc.
- On the other hand, intake of methanol even in very small quantities can cause death .
- Methanol affects optic nerves and causes blindness .
- It is also oxidized to methanal in the liver which reacts rapidly with the cells leading to the coagulation of protoplasm .
Note: Since ethanol is widely used for industrial applications, to avoid any misuse, it is made unfit for drinking by adding methanol to it. Dyes are also added so that it can be easily identified. This is known as denatured alcohol .