Acid rain is an event caused by pollution in the atmosphere. In large urban centers and areas of large industries, there is an excess of polluting gases in the air that cause this phenomenon, rain loaded with large amounts of acids .
The pollutants responsible for the formation of this atmospheric phenomenon are sulfur trioxide and nitrogen dioxide.
Sulfur trioxide is formed from the reaction of sulfur dioxide with the oxygen present in the air. Sulfur dioxide is released into the atmosphere from the burning of fossil fuels, which generally contain sulfur as a contaminant.
Nitrogen dioxide is also released by the combustion reaction.
These two components, once present in the atmospheric air, come into contact with the water that is present in the humidity of the air, undergo a reaction and form sulfuric acid, through sulfur dioxide, nitric acid and nitrous acid, through sulfur dioxide. of nitrogen.
These acids are characterized on the acidity scale as strong acids, with low pH values when in aqueous solution.
Once these acids are formed in the atmosphere in the gaseous form, they join with the water that suffers precipitation from the rain and are carried away, forming an acidic aqueous solution, which is called acid rain.
The phenomenon of acid rain can also be observed in unpolluted places. This is because the components that form acid rain can be carried along with the air masses and thus contaminate other regions.
Carbon dioxide, CO2, present in the atmosphere also reacts with water to form carbonic acid. The fact is that this acid is a weak acid and therefore the rain in this case has low acidity with a pH around 5.4.
pH 7 is considered neutral. A solution with a pH of 5.4 is not considered too acidic to cause serious harm. The water found in nature has a pH around 6. Comparing these values, we realize that the acidity caused in this case is not a big problem.
However, the excessive concentration of acid-forming gases in the atmosphere can increase the acidity, presenting a very low pH of the rain, becoming harmful to the environment.
consequences of acid rain
can cause major problems for the environment. Acidity is corrosive and can destroy historic monuments and cause serious damage to the environment.
Animals and plants of aquatic life do not survive in environments with high acidity. Acid rain precipitation will contaminate rivers and lakes causing the death of these animals.
The soil must be prepared considering criteria of acidity and availability of nutrients to grow food. Acid rain can cause an imbalance in the soil making it unviable for planting. In addition to a number of other damages that acidity can cause.
