The Correct Answer and Explanation is:
The balanced chemical equation is:
S + O₂ → SO₂
This reaction involves elemental sulfur reacting with molecular oxygen to produce sulfur dioxide, a common gas in atmospheric and industrial chemistry.
Explanation
This equation represents a synthesis reaction, which is a type of chemical process where two or more simple substances combine to form a more complex compound. In this case, elemental sulfur (S) reacts with diatomic oxygen (O₂) to form sulfur dioxide (SO₂). Sulfur and oxygen are both nonmetals, so they combine through covalent bonding.
To analyze the reaction step by step: each sulfur atom needs to bond with two oxygen atoms to form one molecule of sulfur dioxide. However, since oxygen naturally exists as diatomic molecules (O₂), one O₂ molecule provides the two oxygen atoms needed for the reaction. Thus, one sulfur atom reacts with one oxygen molecule to yield one molecule of SO₂. This ensures that both mass and atoms are conserved in accordance with the Law of Conservation of Matter.
This reaction commonly occurs in both natural and industrial environments. For instance, it can happen during volcanic eruptions where sulfur from magma comes into contact with atmospheric oxygen. It is also used industrially in the production of sulfuric acid, which is one of the most widely manufactured chemicals in the world. When sulfur dioxide dissolves in water, it forms sulfurous acid, contributing to acid rain when present in the atmosphere. This highlights both the practical and environmental significance of the reaction.
Notably, the equation is already balanced as written. There is one sulfur atom and two oxygen atoms on both sides of the equation. No coefficients are needed. The simplicity of this reaction makes it an excellent example of direct combination and molecular stoichiometry at work.
