Ethanol – Definition, Properties, Uses, Harmful Effects

We can benefit from a large number of organic compounds. Ethyl alcohol also called ethanol is a commercially important organic compound. The physical and chemical properties and uses of ethyl alcohol are discussed below. 

What is Ethyl Alcohol?

The first member of the homologous series of alcohol is methanol. Ethanol is the second member of the homologous series of alcohol. The formula of ethanol is C₂H₅OH. Ethanol is also known as ethyl alcohol. Ethanol is the most prevalent and commonly used alcohol, and it is sometimes referred to simply as alcohol. 

The fermentation of carbohydrates (the method used for alcoholic beverages) and the hydration of ethylene are the two basic processes for producing ethanol. Fermentation is the process of converting carbohydrates to ethanol using yeast cells. Sugar crops like beets and sugarcane, as well as grain crops like corn, are the most common raw materials fermented for the manufacturing of industrial alcohol. The hydration of ethylene is accomplished by passing a mixture of ethylene and a large excess of steam over an acidic catalyst at high temperatures and pressure.

Physical Properties of Ethyl Alcohol.

The following are some of the physical properties of ethyl alcohol:

• It’s a colourless liquid with a pleasant odour and a burning flavour.
• It’s a volatile liquid with a low boiling point of 78⁰C.
• It has a lower density than water. It can be mixed with water in any ratio. The presence of a hydroxyl group in ethyl alcohol contributes to its water solubility.
• It is a neutral compound since it contains no hydrogen ions. As a result, no litmus solution is altered by ethyl alcohol.
• Ethyl alcohol is a covalent compound.
• The term “rectified spirit” refers to ethyl alcohol that contains 5% water. Absolute alcohol refers to 100% pure ethyl alcohol.

Chemical Properties of Ethyl Alcohol.

The following are some of the chemical properties of ethyl alcohol:

• Combustion- The liquid ethyl alcohol is extremely flammable. It easily catches fire and begins to burn. It quickly burns in the air, producing carbon dioxide and water vapour as well as a large amount of heat and light.

C₂H₅OH      +       3O₂          →       2CO₂        +        3H₂O        +   Heat   +    Light
(Ethyl alcohol)      (Oxygen)             (Carbon dioxide)    (Water vapour)                               

• Oxidation- Controlled combustion is referred to as oxidation. Ethyl alcohol is oxidized to ethanoic acid when heated with an alkaline potassium permanganate solution of acidified potassium dichromate solution. To perform this reaction, dropwise add a 5% aqueous potassium permanganate in sodium hydroxide solution to ethyl alcohol until the purple colour of the potassium permanganate solution no longer exists. Ethyl alcohol is oxidized to ethanoic acid when the test tube holding ethyl alcohol and alkaline potassium permanganate solution is gently warmed in hot water. This reaction, which is carried out in the presence of alkaline potassium permanganate solution, is given below.

CH₃CH₂OH      +      2[O]                    →               CH₃COOH             +          H₂O
(Ethyl alcohol)      (Nascent oxygen) (Ethanoic acid)                  (Water)

• Dehydration- Dehydration refers to the loss of water molecules from alcohol. When ethyl alcohol is heated to 170⁰C with excess concentrated sulfuric acid, it dehydrates to generate ethene. The concentrated sulphuric acid acts as a dehydrating agent, removing water molecules from the ethyl alcohol molecule in this reaction. At 170⁰C, this reaction takes place in the presence of concentrated H₂SO₄.

CH₃CH₂OH       →       CH₂=CH₂        +       H₂O
(Ethyl alcohol)                  (Ethene)                  (Water)

• Reaction with Sodium Metal- Sodium ethoxide and hydrogen gas are formed when ethyl alcohol reacts with sodium. This reaction is used to detect the presence of ethyl alcohol.

2C₂H₅OH          +         2Na           →            2C₂H₅O^–Na⁺                  +          H₂
(Ethyl alcohol)               (Sodium)                    (Sodium ethoxide)                   (Hydrogen)

• Reaction with Ethanoic Acid- When ethyl alcohol is heated in the presence of a few drops of strong sulphuric acid, it combines with ethanoic acid to form ethyl ethanoate, a sweet-smelling ester. Esterification is the reaction in which a carboxylic acid reacts with an alcohol to form an ester.

C₂H₅OH          +          CH₃COOH                   →          CH₃COOC₂H₅                   H₂O
(Ethyl alcohol)                (Ethanoic acid)                          (Ethyl ethanoate)              (Water)

Uses of Ethyl Alcohol

• Alcoholic beverages, solvents, fragrances, flavourings, medications, chemical synthesis, and thermometers all employ ethanol.
• Ethyl alcohol is a fuel, a good solvent. Many organic compounds which are invaluable in water, are soluble in ethyl alcohol.
• Ethyl alcohol is a key ingredient in the production of other chemicals.
• Along with petrol, ethyl alcohol is utilized as a fuel in automobiles. It’s also employed as a source of energy in spirit lamps.
• In hospitals and dispensaries, ethyl alcohol is used as an antiseptic to sterilize wounds and syringes.

Harmful Effects of Drinking Alcohol

We should not consume alcoholic beverages because of the following negative consequences.

1. When you consume a large amount of alcohol on a single occasion, you will experience staggering movement, slurred speech, blurred vision, dizziness, and vomiting. A man becomes unconscious after consuming large amounts of alcohol and may even die.
2. Since alcohol reduces the activity of the nerve system and the brain, a person’s judgement is compromised and his reaction is slowed. As a result, a driver under the influence of alcohol is unable to assess the situation accurately or respond swiftly in an emergency. As a result, drunken driving causes a rise in traffic accidents.
3. Drinking a lot of alcohol for a long time can harm your stomach, liver, heart, and even your brain. Alcohol-induced liver damage, known as ‘cirrhosis,’ can be fatal.
4. As a result of the loss of inhibitions caused by alcohol consumption, a drunken person gets irritable. As a result, there are more quarrels and clashes, which leads to a rise in violence and crime in society.
5. A person who consumes a lot of alcohol becomes addicted to it.
6. Drinking methyl alcohol-containing contaminated alcohol produces severe poisoning, which can result in blindness and even death.

Denatured Alcohol

In the manufacturing of various items, a lot of ethyl alcohol is used. The government does not charge a production tax on ethyl alcohol used for industrial purposes. As a result, industrial alcohol is significantly less expensive than commercial alcohol. To prevent industrial alcohol from being used for drinking or black market purposes, it is denatured by adding small amounts of harmful substances such as methanol, pyridine, or copper sulphate, among others. 

The harmful compounds added to ethyl alcohol make it unfit for consumption. Denatured alcohol is ethyl alcohol that has been made unfit for drinking by adding small amounts of harmful substances such as methanol, pyridine, copper sulphate, and other poisonous substances. A little amount of copper sulphate is added to industrial ethyl alcohol to give it a blue colour that makes it easy to identify.

Solved Questions

Question 1: What makes ethyl alcohol to be flammable?

Answer:

Ethanol, like all carbohydrates, is flammable, because it will combine relatively well with oxygen, releasing carbon dioxide and water as waste products.

Question 2: What is the melting point of ethyl alcohol?

Answer:

The melting point of ethyl alcohol is -114.1⁰C.

Question 3: What makes ethyl alcohol such a good solvent?

Answer:

Ethanol is a very polar molecule with high oxygen electronegativity, allowing for hydrogen bonding with other molecules, due to its hydroxyl (OH) group. As a result, ethanol can be used as a solvent to dissolve both polar and non-polar compounds.

Question 4: Why is alcohol included in cough medicine?

Answer:

Alcohol is found in many cough and cold liquids as well as other treatments because it is used in the formulation to help dissolve active components and preserve the product.

Question 5: Give a reason why is ethyl alcohol used as a fuel?

Answer:

Ethyl alcohol burns with clear flame giving a lot of heat, therefore it is used as a fuel.