Shown here are four representations chemists use for sulfuric acid. In the colored models, sulfur is yellow, oxygen is red, and hydrogen is white.
Click on image for full size
Windows to the Universe original artwork by Randy Russell.

Sulfuric Acid - H2SO4

Sulfuric acid is a viscous, oily liquid and a strong acid which can cause severe burns. Sulfuric acid consists of sulfur, oxygen, and hydrogen atoms.

Sulfuric acid is one of the components of acid rain. Some types of pollution, especially the gases formed by the combustion of sulfur-rich coal and oil, contain sulfur dioxide (SO2). When mixed with droplets of water in Earth's atmosphere, sulfur dioxide gas changes to sulfur trioxide (SO3) and then to sulfuric acid. These droplets containing sulfuric acid fall from the sky as acid rain.

Humans produce more than 100 million tons of sulfuric acid worldwide each year. In fact, water is the only chemical compound we produce more of! Sulfuric acid is used in the production of phosphate fertilizers, for processing ores and wastewater, in the refining of oil and other petroleum products, and in the manufacture of some dyes. Lead-acid batteries (such as car batteries) and drain cleaners contain sulfuric acid.

Both natural and human sources release millions of tons of sulfur dioxide gas into Earth's atmosphere each year. Volcanoes are nature's main sulfur dioxide polluters. The oceans, biological decay, and forest fires are other natural sources of SO2. About three-fourths of the sulfur dioxide humans release comes from burning fossil fuels; half comes from burning coal, and 25-30% comes from burning oil. Other human-generated sources include smelting, the manufacture of sulphuric acid, conversion of wood pulp to paper, and the incineration of refuse. As mentioned above, some of the sulfur dioxide in the atmosphere is converted into sulfuric acid upon contact with water, and is thus a major source of acid rain.

The hot atmosphere of the planet Venus contains sulfuric acid, making it difficult to build spacecraft that can withstand the harsh Venusian atmosphere.

This well-known ditty warns of the dangers of consuming sulfuric acid:

Little Johnny took a drink, but he shall drink no more.
For what he thought was H2O, was H2SO4.
Last modified February 3, 2006 by Randy Russell.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more


Oxygen is a chemical element with an atomic number of 8 (it has eight protons in its nucleus). Oxygen forms a chemical compound (O2) of two atoms which is a colorless gas at normal temperatures and pressures....more

Acid Rain

Acid rain is a general term used to describe different kinds of acidic air pollution. Although some acidic air pollutants return directly back to Earth, a lot of it returns in rain, snow, sleet, hail,...more

Air Pollution

What do smog, acid rain, carbon monoxide, fossil fuel exhausts, and tropospheric ozone have in common? They are all examples of air pollution. Air pollution is not new. As far back as the 13 th century,...more

Air Pollution and Water

Many people are aware of the fact that water can be contaminated from trash, oil spills, sewage, fertilizers, and chemicals from factories. Few realize that water can also be contaminated from air pollution...more

Air Pollution Sources

Air pollution comes from many different sources. Natural processes that affect air quality include volcanic activity, which produce sulfur, chlorine, and ash particulates, and wildfires, which produce...more

Atmospheric Chemistry of Earth's Troposphere

Chemistry plays an influential role in the behavior of the lowest layer of Earth's atmosphere, the troposphere. The various gases in the troposphere are constantly mixing with and reacting with each other....more

Ammonia - NH3

Ammonia is a chemical compound that is a colorless, flammable gas at normal temperatures and pressures. Ammonia is toxic, corrosive to some materials, and has a pungent odor. An ammonia molecule (NH3)...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA