~ OH MY GOD!!! ~

Why the umbrella spoiled??????
It’s all ACID RAIN fault!!!!

"It has often been observed that the stones and bricks of buildings crumble more readily in large towns where much coal is burnt.... I was led to attribute this effect to the slow but constant action of acid rain." Robert Angus Smith 1856

"Acid rain" is a popular term referring to the deposition of wet (rain, snow, sleet, fog and cloudwater, dew) and dry (acidifying particles and gases) acidic components. A more accurate term is “acid deposition”.

Unpolluted rain

“Clean” or unpolluted rain has a slightly acidic pH of about 5.2, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid (pH 5.6 in distilled water), but unpolluted rain also contains other chemicals.

H2O(l) + CO2(g) → H2CO3(aq)

Carbonic acid then can ionize in water forming low concentrations of hydronium and carbonate ions:

2 H2O (l) + H2CO3 (aq) CO32− (aq) + 2 H3O+ (aq)

Acid rain

Acid rain is rain or any other form of precipitation that is unusually acidic. It has harmful effects on plants, aquatic animals, and infrastructure. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the atmosphere to produce acids. The sulfur and nittrogen compounds from human sources, such as electricity generation, factories, and motor vehicles. Acid rain has acidity about pH 5.0 or less. Most acid deposition ranges from pH 4.3 to 5.0. For industries areas, pH 2.4 and below can be found.

pH scale to show the pH diference between unpolluted rain and acid rain

Formation of acid rain

Combustion of fuels creates sulfur dioxide and nitric oxides. They are converted into sulfuric acid and nitric acid.

Gas phase chemistry

In the gas phase sulfur dioxide is oxidized by reaction with the hydroxyl radical via an intermolecular reaction :

SO2 + OH· → HOSO2·

which is followed by:

HOSO2· + O2 → HO2· + SO3

In the presence of water, sulfur trioxide (SO3) is converted rapidly to sulfuric acid:

SO3 (g) + H2O (l) → H2SO4 (l)

Nitrgen dioxide reacts with OH to form nitric acid:

NO2 + OH· → HNO3

Chemistry in cloud droplets

When clouds are present, the loss rate of SO2 is faster than can be explained by gas phase chemistry alone. This is due to reactions in the liquid water droplets.

Hydrolysis
Sulfur dioxide dissolves in water and then, like carbon dioxide, hydrolyses in a series of equilibrium reactions:

SO2 (g) + H2O SO2·H2O
SO2·H2O H+ + HSO3−
HSO3- H+ + SO32−

Oxidation
There are a large number of aqueous reactions that oxidize sulfur from S(IV) to S(VI), leading to the formation of sulfuric acid. The most important oxidation reactions are with oozone, hydrogen peroxide and oxygen (reactions with oxygen are catalyzed by iron and manganese in the cloud droplets).

The formation of acid rain

The harmful effects

1) Surface waters and aquatic animals
-- Both the lower pH and higher aluminum concentrations in surface water that occur as a result of acid rain can cause damage to fish and other aquatic animals. At pHs lower than 5 most fish eggs will not hatch and lower pHs can kill adult fish.

2) Soils
-- Some microbes are unable to tolerate changes to low pHs and are killed. The enzymes of these microbes are denatured (changed in shape so they no longer function) by the acid. The hydronium ions of acid rain also mobilize toxins such as aluminium, and leach away essential nutrients and minerals such as magnesium.

2 H+ (aq) + Mg2+ (clay) 2 H+ (clay) + Mg2+ (aq)

3) Forest
-- High altitude forests are especially vulnerable as they are often surrounded by clouds and fog which are more acidic than rain. Other plants can also be damaged by acid rain.

"Bald tree”- without leaves!!!

4) Building and Historical monuments
-- Damage to certain building materials and historical monuments. This results when the sulfuric acid in the rain chemically reacts with the calcium compounds in the stones (limestone, sandstone, marble and granite) to create gypsum, which then flakes off.

CaCO3 (s) + H2SO4 (aq) CaSO4 (aq) + CO2 (g) + H2O (l)

India’s Taj- Mahal which also affected by acid rain. The mausoleum built by the Mughal Emperor Shah Jahan for his beloved wife Mumtaz Mahal is losing its white luster and turning a sickly pale shade.

The corroded monuments

5) Human health
-- The effects of inhaling particulate matter have been widely studied in humans and animals. It included asthma, lung cancer, cardiovascular issues, and premature death.

This acid rain penomenon let me remember a song in my childhood times~~~

♪ “RAIN RAIN GO AWAY~~~” ♪
Acid rain please go away !!!

♥ We can use car pooling method or try to walk to a destination which is in short distance.
♥ We can use an alternative energy source such as solar energy, wind energy.
♥ Plant a tree!! The tree will absorb some of the polluted air and put out clean, fresh oxygen.
♥ Educate other people. One person really can make a difference; think about if other people thought that way, rather than just saying "Well, if they can do it, I can do it".
♥ We can try the best way to save our mother earth, to save ourselves!!!!

GO GO GO AWAY!!!!