Problem 73 - Chemistry The Molecular Nature of Matter

Question

The formula for the sulfite ion is \(\mathrm{SO}_{3}^{2-}\). What is the formula for sulfuric acid?

Step-by-Step Solution

Answer

The formula for sulfuric acid is \(\mathrm{H}_{2}\mathrm{SO}_{4}\).

Step 1: Understanding the Sulfite Ion

Identify the components of the sulfite ion. It consists of sulfur (S) and oxygen (O) with a total charge of -2. The formula is \(\mathrm{SO}_{3}^{2-}\).

Step 2: Determining the Composition of Sulfuric Acid

Sulfuric acid is composed of sulfur, oxygen, and hydrogen. In sulfuric acid, the sulfur is in its highest oxidation state, and the molecule contains two more oxygen atoms in comparison to the sulfite ion.

Step 3: Writing the Formula for Sulfuric Acid

The formula for sulfuric acid combines the elements sulfur (S), oxygen (O), and hydrogen (H). Because the acid has two hydrogen ions, the formula is \(\mathrm{H}_{2}\mathrm{SO}_{4}\).

Key Concepts

Sulfite Ion

Understanding the basic structure of ions, such as the sulfite ion, is crucial in chemistry. A sulfite ion is made up of sulfur (S) and oxygen (O) and has an overall negative charge of 2, which is indicated by its chemical formula \( \mathrm{SO}_{3}^{2-} \). This charge arises because the ion has gained two electrons, a common characteristic of anions, which are negatively charged ions. Sulfite is a sulphur oxoanion resulting from the removal of a proton from sulfurous acid. It is commonly found in various compounds and industrial chemicals.

The presence of sulfur and oxygen in the sulfite ion lays the foundation for more complex molecules, including sulfuric acid. An understanding of the sulfite ion and its properties is an essential stepping stone to grasping the composition of sulfuric acid in terms of its chemical makeup, which includes an additional hydrogen component.

Chemical Formula

The chemical formula of a compound provides a lot of information about the composition, arrangement, and ratio of atoms within a molecule. A chemical formula is a succinct way of expressing information about the atoms that constitute a particular chemical compound. It identifies each type of element by its chemical symbol and indicates the number of atoms of the element found in each discrete molecule of that compound. For example, the chemical formula \( \mathrm{H}_{2}\mathrm{SO}_{4} \) represents sulfuric acid. The numerals in the subscript tell you how many of each type of atom are present in the acid: two hydrogen (H) atoms, one sulfur (S) atom, and four oxygen (O) atoms.

Understanding chemical formulas is fundamental for students because this notation is the language of chemistry. It helps in predicting the properties and behaviors of different substances, aiding in performing stoichiometric calculations, and understanding the relationships among different compounds, such as how the sulfite ion relates to sulfuric acid.

Oxidation States

The concept of oxidation states is a fundamental aspect of chemistry that describes the degree of oxidation of an atom within a compound. An oxidation state is an indicator of the electron control an atom has relative to the isolated neutral atom. In simple terms, it can be thought of as an imaginary charge that an atom would have if all bonds to atoms of different elements were completely ionic.

Using the sulfite ion and sulfuric acid as examples, the sulfur atom in the sulfite ion has an oxidation state of +4, while in sulfuric acid, it has an oxidation state of +6. This difference indicates that the sulfur atom in sulfuric acid has a higher positive charge due to the loss of electrons as compared to when it is in the sulfite ion. This concept plays a significant role in determining how different compounds will react and combine with each other. Recognizing the changes in oxidation states helps us understand and predict redox reactions, which are reactions involving the transfer of electrons.