what is an acid rain? how is it formed?

Question

can u pls tell me what is an acid rain
and how is acid rain formed?

Answer 1

its formed when oxides of sulpur, carbon (given out by industries), in d atmosphere come in contact with the water, and form acids. (sulphuric acid, carbonic acid,... etc)

Answer 2

Acid rain

Precipitation that incorporates anthropogenic acids and acidic materials. The deposition of acidic materials on the Earth's surface occurs in both wet and dry forms as rain, snow, fog, dry particles, and gases. Although 30% or more of the total deposition may be dry, very little information that is specific to this dry form is available. In contrast, there is a large and expanding body of information related to the wet form: acid rain or acid precipitation. Acid precipitation, strictly defined, contains a greater concentration of hydrogen (H+) than of hydroxyl (OH?) ions, resulting in a solution pH less than 7. Under this definition, nearly all precipitation is acidic. The phenomenon of acid deposition, however, is generally regarded as being anthropogenic, that is, resulting from human activity.

Theoretically, the natural acidity of precipitation corresponds to a pH of 5.6, which represents the pH of pure water in equilibrium with atmospheric concentrations of carbon dioxide. Atmospheric moisture, however, is not pure, and its interaction with ammonia, oxides of nitrogen and sulfur, and windblown dust results in a pH between 4.9 and 6.5 for most “natural” precipitation. The distribution and magnitude of precipitation pH in the United States (illustration) suggest the impact of anthropogenic rather than natural causes. The areas of highest precipitation acidity (lowest pH) correspond to areas within and downwind of heavy industrialization and urbanization where emissions of sulfur and nitrogen oxides are high. It is with these emissions that the most acidic precipitation is thought to originate.

Answer 3

Right, coal often has trace quantities of Sulphur, which when burned in the presense of moisture produces Sulphuric acid.
The Sulphur dioxide produced from combustion combines with the moistire in the air, to rain down weak sulphuric acid, which damages plants, statues, and ends up in the river, affecting fish ect.

There is a lot of coal around the world, but often has unacceptable amounts of Sulphur making it nearly useless.
Oil has the same problem, the Sulphur must be removed.

Answer 4

acid rain is the rain that contains sulphuric acid and nitric acid. it is formed due to pollutants in the air.
when the rain is coming down it gets with the pollutants such as sulphur dioxide and nitrogen dioxide which leads to the formation of the acids as the water reacts with the pollutants.

Answer 5

Acid rain is formed due to SO2 emitted from fuel-burning. SO2 reacts with rain water to formed H2SO3. This sulhurous acid reacts further with oxygen and water to form sulphuric acid which is H2SO4, acid rain. Acid rain corrodes building and stonework containing carbonate (usually calcium carbonate) and acidify soil and river water.

Answer 6

WHAT ARE ACIDS?

There are many different kinds of acids. The proteins in our food, and in our bodies, are made up of amino acids. Motor cars start because of the sulphuric acid in their batteries. Swimming pools need hydrochloric acid, commonly known as `pool acid'.

Some acids are weak, e.g acetic acid (vinegar) and lemon juice. They are not harmful and are used in preparing our food. Othershowever, such as sulphuric acid (battery acid) are strong and can burn holes in our clothes.

WHAT SHOULD RAIN BE LIKE?

The only place on earth where pure water is found is in a laboratory. Rain water always contains small amounts of impurities. These impurities come from dust particles or are absorbed from the gases in the air.

If pure water is exposed to the air it absorbs carbon dioxide to form carbonic acid and becomes slightly acidic, dropping from pH 7 i.e. neutral, to pH 5,6. Even in remote, unpopulated areas rain can reach a pH of 4,5. However, a pH of less than 4,5 in rain is almost certainly caused by pollution.

HOW ACID RAIN IS FORMED

Acid rain is caused by the release of the gases SO2 (sulphur dioxide) and NOX (nitrous oxides). The main sources of SO2 in South Africa are coal-fired power stations and metal working industries. The main sources of NOX emissions are vehicles and fuel combustion.

Sulphur dioxide reacts with water vapour and sunlight to form sulphuric acid. Likewise NOX form nitric acid in the air. These reactions takes hours, or even days, during which polluted air may move hundreds of kilometres. Thus acid rain can fall far from the source of pollution.

When mist or fog droplets condense they will remove pollutants from the air and can become more strongly acid than acid rain. Even snow can be acid. Gases and particles, not dissolved in water, with a low pH can also be deposited directly onto soil, grass and leaves. It is possible that even more acidity is deposited in this way than by rain! Not much is known about this process, and it is particularly difficult to study.

EFFECTS OF ACID RAIN

* Acid rain can increase the acidity of lakes, dams and streams and cause the death of aquatic life.

* Acid rain can increase the acidity of soil, water and shallow groundwater.

* Acid rain has been linked with the death of trees in Europe and North America. In spite of a great deal of research, no one yet knows exactly how acid rain harms forests. Most of the forests of Europe consist of huge areas of one tree species. This encourages the spread of plant pests and diseases. It seems likely that acid rain weakens the trees, perhaps helped by other pollutants such as ozone, and then leaves the trees open to attack by disease. Acid rain also disrupts the availability of soil nutrients. The final death of a tree may result from a combination of stresses such as heat, cold, drought, nutrient disruption and disease. It seems that the slow-growing, longer lived forests of the North may be more susceptible than the faster growing, shorter lived forests of South Africa.

* Acid rain erodes buildings and monuments. Acid particles in the air are suspected of contributing to respiratory problems in people.

ACID RAIN IN SOUTH AFRICA

The coal burning power stations and large metal working industries of South Africa are concentrated in the Eastern Transvaal Highveld, the industrial heart of the country. Electricity is distributed nationally from here and many of our exports are produced in this region. This area produces most of the country's pollution: In 1987 it was responsible for 1,84 million tonnes of sulphuric acid and 0,84 million tonnes of nitric acid. Not surprisingly acid rain occurs in this region and can average pH 4,2 and sometimes fall as low as pH 3,7. Whether this is harming our crops or forests is not known. There are some signs of forest damage, but other causes are also possible. Research into this issue is being carried out in South Africa by CSIR, Eskom and other bodies.

Answer 7

From burning fossil fuels.

Answer 8

See http://en.wikipedia.org/wiki/Acid_rain