Ethanol

Ethanol is an organic compound of carbon with the molecular formula of C₂H₅OH, also known as ethyl alcohol or ethyl ethanol. Ethanol is a colourless, volatile liquid identified by a characteristic smell. It is the most used alcohol in the world for the manufacturing of alcoholic beverages, fuel, spirits, industrial products, and solvents.

1.0Ethanol Structure and Properties

• Molecular Formula: C₂H₅OH 
• IUPAC Name: Ethanol 
• Functional Group: Hydroxyl group (–OH)
• Molecular Structure: The molecular structure of Ethanol consists of a chain of two carbons (ethane C2H6) with a hydroxyl group (-OH) bonded at any one end of the carbon. This hydroxyl group makes ethanol a primary alcohol. 
• Density: Ethanol density is approximately 0.789g/cm³ at 20℃. 
• Boiling Point: 78.37℃
• Melting Point: –114.1℃
• Solubility: Ethanol Alcohol is a highly soluble compound in water, making hydrogen bonds with water. 
• Flammability: Ethanol is a highly flammable substance, which is why it is used in manufacturing alcohol burners. 

2.0Types Of Ethanol

Ethanol or Ethyl Alcohol is mainly of two types. Which includes: 

• Denatured Ethanol: Denatured ethanol is ethanol mixed with chemicals to render it undrinkable. This form is often used in industrial applications and for cleaning to avoid alcohol taxes and regulations.
• Absolute Ethanol: This refers to ethanol, which has been purified to remove water content. Absolute ethanol is sometimes called 100% ethanol and is used in laboratories when water-free ethanol is required for chemical reactions and applications as a solvent.

3.0Preparation of Ethanol

Ethanol (C₂H₅OH) can be prepared through several methods, each using different raw materials and processes. The two primary methods for preparing ethanol are fermentation and hydration of ethene. There are also additional methods that involve the reduction of compounds and industrial-scale techniques: 

• Fermentation: It is the process in which we use microorganisms to convert sugars into ethanol. In this process, yeast produces ethanol through the fermentation of sugars. This process is generally applied to make alcoholic beverages. When yeast enzymes break down glucose or other sugars under anaerobic conditions, ethanol is produced. The reaction involved in fermentation is: 

$C_6{H}_{12}{O}_6(Glucose)\to 2C_2{H}_{5}OH(ethanol)+2C{O}_2$

• Hydration of Ethene: Ethanol can also be produced by supplying hydrogen to Ethene in the presence of a catalyst, usually phosphoric acid. The reaction involved is:  

$C_2{H}_4(ethene)+H_{2}O\to C_2{H}_{5}OH(ethanol)$

• Reduction of Acetaldehyde: Ethanol can also be manufactured by performing a reduction reaction of acetaldehyde or ethanal in the presence of Nickel or Palladium catalyst. This method is used for the production of ethanol on an industrial scale. 

$C{H}_{3}CHO+H_2\to C_2{H}_{5}OH$

4.0Reactions Related to Ethanol

Ethanol undergoes various chemical reactions with different compounds, proving its versatility in organic chemistry. Some key reactions are: 

1. Combustion Reaction: When ethanol burns, it reacts with oxygen in the atmosphere to produce carbon dioxide and water, releasing energy.

$C_2{H}_{5}OH+3O_2\to 2C{O}_2+3H_{2}O+Energy$

2. Oxidation Reaction: Ethanol can be oxidised to form acetaldehyde, and further oxidation produces acetic acid, known as vinegar. This process is used in the industrial production of acetic acid.

• Partial Oxidation: 

$C_2{H}_{5}OH\to C{H}_{3}CHO(Acetaldehyde)+H_{2}O$

• Complete Oxidation: 

$C_2{H}_{5}OH+O_2\to C{H}_{3}COOH(AceticAcid)$

3. Reaction with Sodium: Like any other alcohol, Ethanol reacts with sodium to form sodium ethoxide and hydrogen gas. 

$2C_2{H}_{5}OH+2Na\to 2C_2{H}_{5}ONa+H_2$

4. Dehydration: This reaction is used to convert Ethanol to Ethene. When ethanol is heated in the presence of a catalyst such as concentrated sulfuric acid, it is dehydrated to yield ethene. 

$C_2{H}_{5}OH\to C_2{H}_4+H_{2}O$

5.0Phenyl Ethanol (C₆H₅CH₂CH₂OH)

This is an aromatic alcohol with a phenyl group (C₆H₅) attached to the chain of ethanol. It is a colourless liquid that smells sweet and floral, and for this reason, it is used in the fragrance and flavour industry, mainly for fragrances that particularly smell rosey. Unlike Ethanol, it is not very soluble in water; instead, it is soluble in another organic solvent. 

Structure of Phenyl Ethanol: 

• The molecule has a benzene ring (C₆H₅) attached to a two-carbon chain where the hydroxyl group (–OH) is connected to the second carbon.
• Chemical formula: C₆H₅CH₂CH₂OH
• Functional group: Hydroxyl group (-OH). 

Isomers of Phenyl Ethanol

Isomers refer to chemical compounds having the same molecular formula but differing in the type of arrangement of the atoms or the spatial orientation of their atoms. Differences in the structure then result in different physical and chemical properties. Phenyl Ethanol also has two isomers: 

• 2-Phenyl Ethanol: The phenyl group is attached to the second carbon atom.
• 1-Phenyl Ethanol: The phenyl group is attached to the first carbon atom.

6.0Uses Of Ethanol 

Ethanol is used for a wide variety of areas in various industries, some of them are as follows: 

• Alcoholic Beverages: Ethanol is the main ingredient in alcoholic beverages, such as beer, wine, and spirits. It is obtained through fermentation.
• Fuel: Ethanol is a source of fuel, particularly as a biofuel. Ethanol is also often blended with gasoline to make ethanol-blended fuels that cut the usage of fossil fuels. Absolute or 100% ethanol is used as an alternative fuel in some places.
• Solvent: Ethanol is a very good solvent since it can dissolve both polar and nonpolar substances. It is used in the manufacture of perfumes, cosmetics, pharmaceuticals, paints, and cleaners.
• Disinfectants: Ethanol acts as an antiseptic and disinfectant because of its bactericidal and virucidal effects, which are employed in medical wipes and hand sanitisers.
• Industrial Use: Ethanol is used to produce several chemicals, including acetic acid and ethyl acetate, and plastics, detergents, and flavouring agents.