There are numerous uses for acids. Acids are often used to remove rust and other corrosion from metals in a process known as pickling.
1. Sulfuric acid in a car battery/mineral processing.
2. Nitric acid reacts with ammonia (neutralization reactions) to produce ammonium nitrate, a fertilizer.
3. Acids are used as additives to drinks and foods, as they alter their taste and serve as preservatives.
a. Phosphoric acid, for example, is a component of cola drinks.
b. Acetic acid is used in day to day life as vinegar.
c. Carbonic acid is an important part of some cola drinks and soda.
d. Citric acid is used as a preservative in sauces and pickles.
4. Tartaric acid is an important component of some commonly used foods like unripened mangoes and tamarind.
5. Natural fruits and vegetables also contain acids.
a. Citric acid is present in oranges, lemon and other citrus fruits.
b. Oxalic acid is present in tomatoes, spinach, and especially in carambola and rhubarb; rhubarb leaves and unripe carambolas are toxic because of high concentrations of oxalic acid.
6. Ascorbic acid (Vitamin C) is an essential vitamin required in our body and is present in such foods as amla, lemon, citrus fruits, and guava.
7. Certain acids are used as drugs. Acetylsalicylic acid (Aspirin) is used as a pain killer and for bringing down fevers.
8. Acids play very important roles in the human body.
a. The hydrochloric acid present in our stomach aids in digestion by breaking down large and complex food molecules.
b. Amino acids are required for synthesis of proteins required for growth and repair of our body tissues.
c. Fatty acids are also required for growth and repair of body tissues.
d. Nucleic acids are important for the manufacturing of DNA, RNA and transmission of characters to offspring through genes.
e. Carbonic acid is important for maintenance of pH equilibrium in the body.
The uses of alkali in daily life
1. Environmental Uses
· Alkalis can help soften potable water and remove impurities such as manganese, fluorides and organic tannins. According to the National Lime Association, heavy industries use alkali in the form of lime to absorb and neutralize sulphur oxides to aid in reducing acid rain.
2. Lake Treatment
· Sulphuric dioxide produced by industries and released into the atmosphere returns as acid rain or sulphuric acid. In lakes impacted by acid rain, such as in Ontario, Canada, the application of alkalis dropped by airplanes can control and neutralize the water's pH level.
3. Sewage Treatment
· Alkalis can convert waste products by maintaining the correct pH for oxidation of sewage. Applying alkali can stabilize sewage sludge, and reduce odor or bacteria. Dewatering the sludge, then adding lime or quicklime meets the U.S. government criteria regarding treatment for reducing pathogens. This treated sludge then can act as a soil conditioner on farm land.
4. Industrial Applications
· For industrial and mining operations, applying alkalis to wastewater can remove phosphors and nitrogen and improve clarity. Excess-alkalinity treatment raises the pH of water to 10.5 to 11 and can disinfect the water and remove heavy metals. Alkalis such as lime are key in the chemical production of calcium carbide, citric acid, petrochemicals and magnesia. In the paper industry, calcium carbonate is a causticizing agent for bleaching. The steel industry depends on lime to act as a flux to remove impurities such as gaseous carbon monoxide, silicon, manganese and phosphorus.
5. Detergents
· Alkaline detergents aid in hard surface cleaning. These economical, water-soluble alkalis with a pH from 9 to 12.5 can neutralize acids in different types of dirt and soil. These detergents can remove scuff marks, water emulsion waxes and accumulated dirt.
6. Ceramic Products: Glass and Glazes
· Alkalis are a principal raw material in glass. Limestone, as well as sand, soda ash, lime and other chemicals, are fired at extremely high temperatures and transformed into a molten mass. Potters use alkalis for glazes and body fluxes that react with acids to form silicates or glasses when heated. Stronger alkalis create a brighter colour response in glazes.
