Which acids are present in acid rain

When rainwater is too acidic, it can cause problems ranging from killing freshwater fish and damaging crops, to eroding buildings and monuments. Write a balanced chemical equation for the dissociation of nitric acid in water. The gaseous oxides found in the atmosphere, including CO 2 and NO are nonmetal oxides.

What would happen to the pH of rainwater if the atmosphere contained metal oxides instead? Briefly, explain your answer. What causes such a dramatic increase in the acidity of rain relative to pure water? The answer lies within the concentrations of nitric oxide and sulfur dioxide in polluted air.

As shown in Table II and Figure 1, the concentrations of these oxides are much higher than in clean air. Humans cause many combustion processes that dramatically increase the concentrations of acid-producing oxides in the atmosphere. Thus, a large increase in the concentration of NO and SO 2 significantly affects the pH of rainwater, even though both gases are present at much lower concentration than CO 2. About one-fourth of the acidity of rain is accounted for by nitric acid HNO 3.

In addition to the natural processes that form small amounts of nitric acid in rainwater, high-temperature air combustion, such as occurs in car engines and power plants, produces large amounts of NO gas. This gas then forms nitric acid via Equations 4 and 5. Thus, a process that occurs naturally at levels tolerable by the environment can harm the environment when human activity causes the process e.

Most is accounted for by the presence of sulfuric acid H 2 SO 4 in rainwater. Although sulfuric acid may be produced naturally in small quantities from biological decay and volcanic activity Figure 1 , it is produced almost entirely by human activity, especially the combustion of sulfur-containing fossil fuels in power plants. When these fossil fuels are burned, the sulfur contained in them reacts with oxygen from the air to form sulfur dioxide SO 2.

The effects of burning fossil fuels can be dramatic: in contrast to the unpolluted atmospheric SO 2 concentration of 0 to 0. Sulfur dioxide, like the oxides of carbon and nitrogen, reacts with water to form sulfuric acid Equation 6. At sea level and 25 o C, one mole of air fills a volume of Compute the mole fraction i.

One strategy for limiting the amount of acid pollution in the atmosphere is scrubbing. In particular, calcium oxide CaO is injected into the combustion chamber of a power plant, where it reacts with the sulfur dioxide produced, to yield solid calcium sulfite. Write a balanced chemical equation for this reaction. HINT: Consult the table of common ions in the tutorial assignment for Experiment 1 to view the structure and formula for sulfite; also, use your knowledge of the periodic table to deduce the charge of the calcium ion.

Using these facts, you can deduce the formula for calcium sulfite. Approximately one ton, or 9. How much sulfur dioxide in moles is prevented from entering the atmosphere when this much calcium sulfite is generated? Show your calculation. Many buildings and monuments are made of stone, and many buildings use stone for decorative trim. Granite is now the most widely used stone for buildings, monuments, and bridges.

Limestone is the second most used building stone. It was widely used before Portland cement became available in the early 19th century because of its uniform color and texture and because it could be easily carved. Sandstone from local sources was commonly used in the Northeastern United States, especially before Nationwide, marble is used much less often than the other stone types, but it has been used for many buildings and monuments of historical significance.

Because of their composition, some stones are more likely to be damaged by acidic deposition than others. Granite is primarily composed of silicate minerals, like feldspar and quartz, which are resistant to acid attack. Sandstone is also primarily composed of silica and is thus resistant.

A few sandstones are less resistant because they contain a carbonate cement that dissolves readily in weak acid. Limestone and marble are primarily composed of the mineral calcite calcium carbonate , which dissolves readily in weak acid; in fact, this characteristic is often used to identify the mineral calcite. Acid precipitation affects stone primarily in two ways: dissolution and alteration.

When sulfurous, sulfuric, and nitric acids in polluted air react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive.

You might expect that sheltered areas of stone buildings and monuments would not be affected by acid precipitation. However, sheltered areas on limestone and marble buildings and monuments show blackened crusts that have spalled peeled off in some places, revealing crumbling stone beneath. This black crust is primarily composed of gypsum, a mineral that forms from the reaction between calcite, water, and sulfuric acid.

Gypsum is soluble in water ; although it can form anywhere on carbonate stone surfaces that are exposed to sulfur dioxide gas SO 2 , it is usually washed away. It remains only on protected surfaces that are not directly washed by the rain. Gypsum is white, but the crystals form networks that trap particles of dirt and pollutants, so the crust looks black.

Eventually the black crusts blister and spall off, revealing crumbling stone. Want to learn more about acid rain and water? Follow me to the Acid Rain website! The USGS has been at the forefront of studying the impacts of acid rain for decades. How does acid rain form? What does it do to the landscape? Can it burn you like battery acid? Keep reading to find out more Water is everywhere, which is fortunate for all of humanity, as water is essential for life.

Even though water is not always available in the needed quantity and quality for all people everywhere, people have learned to get and use water for all of their water needs, from drinking, cleaning, irrigating crops, producing electricity, and for just having fun.

The U. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very One of the goals of research on the effects of acidic deposition on carbonate stone surfaces is to define the incremental impact of acidic deposition relative to natural weathering processes on the rate of carbonate stone erosion.

If rain that impacts carbonate stone surfaces is resident on the surface long enough to approach chemical equilibrium Review of: The acid rain controversy, by Regens, J. The amount of acidity in the atmosphere that deposits to earth through dry deposition depends on the amount of rainfall an area receives. For example, in desert areas the ratio of dry to wet deposition is higher than an area that receives several inches of rain each year.

Unlike wet deposition, dry deposition is difficult and expensive to measure. When acid deposition is washed into lakes and streams, it can cause some to turn acidic.

The Long-Term Monitoring LTM Network measures and monitors surface water chemistry at over sites to provide valuable information on aquatic ecosystem health and how water bodies respond to changes in acid-causing emissions and acid deposition. Skip to main content.

Contact Us. What Causes Acid Rain? Vehicles and heavy equipment.