Simulating the Effects of Acid Rain

Materials Required:
 - Bottle of Vinegar (1/2 cup per group)
- Chalk (two to three pieces per group)
- Zip lock bags (2 per group)
- Droppers (2 per group)
- Plates (2 per group)
- Tap water (1/2 cup per group) 

Procedure:  

• Place one piece of chalk in each pan.
• Using the dropper drip vinegar onto the chalk on one of the plates in a constant stream.
• Using the dropper drip water onto the chalk on the second plate in a constant stream. 

Scientific Explanation: 

Acid rain is caused mostly by the combustion of fossil fuels containing sulfur and nitrogen. When sulphur and nitrogen are combusted, sulphur dioxide and nitrogen oxides are created and released into the atmosphere. Once these gases come in contact with water they become acids (Sulphuric acid and Nitric acid). This can happen either through wet deposition when rain, sleet or snow remove the gases from the air or through dry deposition when particles are deposited and absorbed into surfaces and later converted into acids when they come into contact with water. Coal power plants, electricity generation, driving a car, volcanoes and thunderstorms all contribute to acid rain. While there are natural causes of acid rain as mentioned, 90% of harmful emissions are a result of man-made sources. Acidity of rainwater is measured by the pH scale. It ranges from 0 which is highly acidic to 14 which is highly alkaline (basic). The scale point 7 is neutral. Clean rain measures at pH 5.6 while acid rain is anything measuring between pH 5 and pH 0. Acid rain has an adverse effect on the natural environment including forests, freshwaters and soils. It not only kills insect and aquatic life forms but also causes damage to buildings and has impacts on human health. Acid rain destroys the surface of trees and depletes essential nutrients in the soil greatly impacting plant germination and reproduction, causing vulnerability to disease and stunting its growth. It increases the level of acidity in water sources which inhibits the ability for natural mechanisms to cope. Gradually the most fragile creatures and life forms begin to die. Lastly, acid rain damages buildings through corrosion and fracturing.
 

Great structures such as the Taj Mahal and the Washington Monument buildings have all suffered the harmful effects of acid rain. Buildings made of limestone are particularly impacted.
In order to mimic the effect of acid rain on the environment specifically on rock (limestone) we used vinegar and chalk. It may take a considerable amount of time to see the visible effects of acid rain yet the reaction of vinegar and chalk is instant and illustrates the same concept. The reaction of vinegar and chalk is an example of an acid- base reaction (neutralization). Vinegar, the acid, has a pH level of 3 while the chalk also known as calcium carbonate is a base at pH 8. When they are combined the chalk starts to bubble and foam up. The acid breaks apart the calcium carbonate and produces calcium and carbon dioxide gas. The bubbles you see during the reaction are carbon dioxide. On the surface of the vinegar are small pieces of chalk which have been neutralized.

The Negative Effects Of Ozone Depletion Due To Acid Rain

Acid rain has been around for a long time. It was first noticed around the 17  century during the industrialization period. Scientists have been paying attention to "acid rain" since that time and the effects it has had on the plants, animals, humans etc. Acid rain is very dangerous as most people know. First off the term is not totally correct and scientists prefer the terminology acid depositions. The reason these scientists believe that it is called acid depositions instead of acid rain is simply because the acid which was formed by pollution can in fact return to the earth as either solid or a gas and not only in the form of rain. 

Acid depositions can come in rain, fog or even snow. Industries, factories, vehicles, aerosol cans, etc are all causes for "acid rain". This is because all of these things increase the level of sulphur dioxide and nitrogen in the air we breathe in. These chemicals will later transform into sulphuric acid as well as nitric acid which in the long run will come down in the form of "acid rain". Electric companies have to burn a lot of coal, which contains a very low amount of sulphur, in a day's time which will increase the level of sulphur dioxide in the atmosphere. But the electric companies are not the only one's to blame; a lot of other companies and industries have to process raw ore (a mineral or a numerous amount of minerals which a valuable or constituent can be profitably mined or extracted) so they can obtain copper, zinc, and nickel. 

The problem with that is that copper, zinc, and nickel are also causes of acid rain. Most pollution, if not all, is caused by humans in the formed of vehicles, industries etc. The accidents in which man has no control over such as volcanic eruptions, lightning, decay etc are a cause for the different pollutants in the atmosphere but nothing can be done to avoid this. But this is not a great risk to the atmosphere and us when one considers that 90% of the sulphur dioxide in our atmosphere and 95% of nitrogen oxides is caused by man. Which leaves about 10% and 5% respectively are caused by nature which is very minimal. The biggest problem about "acid rain" is that it does not stay where it was created. Since acid rain takes many forms, it will travel everywhere and create itself somewhere else thru the aid of wind, water, etc. 

The United States is well known to be a big part of the pollutants in the world; for example is it believed that 50% of the "acid rain" in Canada is caused by the pollution in America. It is important to know that pollution is not the only cause of "acid rain". If you take rainfall as an example, even if there is no pollution at all in the atmosphere, the rain itself is still acidic. The rain in rainfalls has a pH of roughly 6.0. The cause of this is because there is carbon dioxide in our atmosphere and when it mixes with water it created carbonic acid. Since this is not a perfect world, there will always be pollution in the world and because of these pollutants it affects the pH level and makes it drop. When the pH level reaches below 5.5 it is classified as "acid rain". The lowest ever recorded pH level was around 2 - 2.5.

Effect of Acid Rain on Lakes and Rivers

It is in aquatic habitats that the effects of acid rain are most obvious. Acid rain runs off the land and ends up in streams, lakes and marshes - the rain also falls directly on these areas.As the acidity of a lake increases, the water becomes clearer and the numbers of fish and other water animals decline. Some species of plant and animal are better able to survive in acidic water than others. Freshwater shrimps, snails, mussels are the most quickly affected by acidification followed by fish such as minnows, salmon and roach. 

Lakes, rivers and marshes each have their own fragile ecosystem with many different species of plants and animals all depending on each other to survive. If a species of fish disappears, the animals which feed on it will gradually disappear too. If the extinct fish used to feed on a particular species of large insect, that insect population will start to grow, which in turn will affect the smaller insects or plankton on which the larger insect feeds.

Life of Aquatic Organisms:
 
Some types of plants and animals are able to tolerate acidic waters. Others, however, are acid-sensitive and will be lost as the pH declines. Generally, the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acid lakes have no fish.

The roe and fry (eggs and young) of the fish are the worst affected as the acidity of the water can prevent eggs from hatching properly, can cause deformity in young fish which also struggle to take in oxygen.The acidity of the water does not just affect species directly, it also causes toxic substances such as aluminum to be released into the water from the soil, harming fish and other aquatic animals.
 
Makes Drinking water unsafe:

Water that is slightly acidic should not be dangerous, as there are many foods that have low pH
value; for example, lemon juice has a pH of 2.4. However, a low pH can indicate that there may
be other contaminants in the water, because if pollutants have been added to a water source,
the pH typically will change.

Water treatment facilities monitor the pH level of the water while they are treating it for
municipal use. Acidic or basic water is harder to disinfect than water with a pH that is closer to
7.0. As well, if acidic water was sent through pipes and into homes, there would be a greater
danger of pipe corrosion, which could allow metals to dissolve into the drinking water as it flow
through the pipes. According to the World Health Organization, a pH less than 8.0 is necessary
for effective chlorination. If the pH is too high, water treatment facilities can decrease the acidity
in a number of ways. One common method that is used to increase the pH is to send the water
through a calcium carbonate filter, which neutralizes the acid and increases the pH of the water. Another common method is to inject a sodium carbonate solution into the water.