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Acid rain is rain that contains sulphuric and nitric acids.
Rainwater which contains sulphuric acid or nitric acid is called acid rain. It is caused by acidic air pollutants such as sulphur dioxide and nitrogen dioxide which react with rainwater.
Sulphur dioxide dissolves readily in water to form sulphurous acid:
SO2(g) + H2O(l) ~~~~~~~> H2SO3(aq)
In the presence of oxygen in the air, this acid is slowly oxidised to sulphuric acid.
Oxides of nitrogen also contribute to acid rain. In the presence of oxygen and water, nitrogen dioxide is converted to nitric acid.
4NO2(g) + 2H2O(l) + O2(g) ~~~~~~> 4HNO3(aq)
What are the effects of acid rain?
Acid rain erodes structures and thus, making them weak. Some famous structures like the Statue of Liberty have been damaged by acid rain.
When acid rain hits the earth, nutrients essential for the trees in the soil are washed away and toxic metals are freed. If the trees absorb these toxic metals, they would die as they are deprived of their vital nutrients, such as calcium and magnesium. Some of the sulphur dioxide in the leaves also may clog up the stomata in the leaves, causing them to eventually fall off.
This reduces the tree's ability to make food.
KILLS MARINE LIFE
Acid rain lowers the pH value of lakes and rivers. In simpler terms, it makes them more acidic. When the water becomes too acidic, the fishes begin to die.
In addition to that, other plants will also disappear. It is said that when the pH value of the water gets to 4.5, pretty much everything in the lakes and rivers are dead.
HEALTH PROBLEMS IN MAN
Acid rain frees the toxic metals which are present in the ground and washes them into water sources. The water eventually gets to our drinking water supply and contaminates it. When the water is acidic enough, it may even corrode the water pipes, adding in dissolved copper and lead to the water supply.
Toxic metals which are absorbed from water by fruits, vegetables, and in the tissues of animals indirectly affect humans. Studies have shown that mercury that accumulates in the organs and tissues of animals has been linked to with brain damage in children, nerve disorders, heart problems and even death.
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