Why do Acids Burn?
Acids are chemicals that convert blue color litmus paper into red. The color of the litmus paper indicates the extent of hydrogen ions in the paper. If the hydrogen ion concentration is lower than pure water then the blue litmus will turn red. If the hydrogen ion concentration is higher than the pure water then the red litmus will turn blue. The pH of pure water is 7 and that of acid is less than 7. The pH of alkali is more than 7.
The acid burns occur when the living tissue is exposed to a strong acid which is corrosive in nature. The strong acids will cause major tissue destruction. The acids do not need any source of heat for causing any damage to the living tissue. They start corroding the tissue as soon as the skin comes in contact with the acid. The acid burns are extremely painful and the burns may not be visible immediately after the accident but will slowly eat away the tissues.
Most of the acids have the tendency to absorb water from the skin and react with it. During this reaction heat is released outside. This type of reaction is called exothermic reaction. This heat will in turn damage the cells instantaneously. Organic matter as well as living cell contains more amount of water with which the acid can react and in this process the cells are killed.
The strong acid dissociates readily in water and produces extensive hydrogen ions and this formation of hydrogen ions is irreversible by nature. The released hydrogen ions create more acidity and cause the damage. Weak acid reaction with water is reversible by nature and they do not release much of hydrogen ions and hence avoids formation of less pH. As there is less acidity, there is also less damage of the tissue. It is concluded that strong acid burns the skin more than the weak acid.
April 23, 2013 2:35 pm
pH = -log [H+], this means that when hydrogen concentration is high, pH is low (acidic). When [H+] is low, the pH will in turn be high (basic). Exposing blue litmus paper to a solution with [H+] lower than water will no change the color of the paper because the solution will still be basic. However, exposing it to red litmus paper will turn it blue. 🙂 AK