What is the name for the compound SO3?
The correct answer and explanation is:
Correct Answer: Sulfur trioxide
Sulfur trioxide is a chemical compound made up of one sulfur (S) atom and three oxygen (O) atoms. It has the molecular formula SO₃. This compound is classified as a covalent compound, meaning it forms through the sharing of electrons between nonmetals.
In naming covalent compounds, Greek prefixes are used to indicate the number of atoms of each element. The element that is less electronegative is written first. In this case, sulfur is less electronegative than oxygen, so it appears first in the name. Since there is only one sulfur atom, the prefix mono- is not used (it is often omitted for the first element if there is only one atom). For the three oxygen atoms, the prefix tri- is used. The root of the element name “oxygen” is changed to “oxide.” Therefore, the correct name is sulfur trioxide.
This compound plays a major role in industrial chemistry. It is a key intermediate in the production of sulfuric acid (H₂SO₄), one of the most widely used chemicals worldwide. Sulfur trioxide is highly reactive and readily dissolves in water, releasing a large amount of heat and forming sulfuric acid. However, direct contact with water can be dangerous due to the violent reaction that produces heat and mist of acid.
Sulfur trioxide is also a significant contributor to air pollution. It forms when sulfur dioxide (SO₂), which is emitted from burning fossil fuels, undergoes further oxidation in the atmosphere. It can combine with water vapor to produce acid rain, which is harmful to plants, buildings, and aquatic ecosystems.
Because of its chemical properties and environmental impact, sulfur trioxide must be handled carefully in laboratories and industrial settings.