11.6 Uses of Alcohol, Aldehydes, and Organic Acids

Alcohol

• Methanol: Methanol (CH₃OH) is toxic and mainly used in the preparation of other chemical substances. It plays a key role in the chemical industry.

• Ethanol:

• Solvent: Ethanol is commonly used as a solvent in industries like perfume, cosmetics, and pharmaceuticals.

• Pharmaceutical Grade Ethanol: Ethanol that meets pharmaceutical standards is used in the pharmaceutical industry.

• Rectified Spirit: A 96% solution of ethanol, known as rectified spirit, is used in homeopathic medicine.

• Methylated Spirit: To make rectified spirit toxic, small amounts of methanol are added, creating methylated spirit. It is used to polish wood and metallic furniture.

• Fuel: In Brazil, ethanol is used as an alternative to fossil fuels for motor engines.

• Production of Ethanol:

• Fermentation: Ethanol can be prepared from starch sources like rice, wheat, potatoes, and corn through fermentation. It can also be obtained from molasses (a by-product of sugar production).

• Local Production: In Bangladesh, Keru & Co at Darshona produces ethanol to meet domestic demands.

• Environmental Impact: Using ethanol as fuel can reduce the demand for fossil fuels and help minimize environmental pollution.

Aldehydes

• Plastic Production: Aldehydes are used in the production of various plastic materials through polymerization reactions.

• Delrin Polymer: Produced by heating methanol in a liquid solution under low pressure, Delrin is used to manufacture products like chairs, dining tables, and buckets.

• Urea-Formaldehyde Resin: A condensation polymerization of formaldehyde and urea creates urea-formaldehyde resin, which is used to make household appliances such as plates, drinking water pots, and mugs.

Organic Acids

• Weaker than Inorganic Acids: Organic acids are weaker than inorganic acids and are edible.

• Common Organic Acids: Citric acid (from lemon juice), tartaric acid (from tamarind), and lactic acid (from curd) are common organic acids we consume in food.

• Food Preservation: Organic acids, due to their antibacterial properties, are commonly used as food preservatives.

• Vinegar: A 4% to 10% solution of ethanoic acid (CH₃COOH) is known as vinegar, which is widely used to preserve sauces and pickles.