Question

Give the proper name for each molecule. a) \(\mathrm{XeF}_{2}\) b) \(\mathrm{O}_{2} \mathrm{~F}_{2}\) c) \(\mathrm{SF}_{6}\)

Short answer

a) Xenon Difluoride, b) Dioxygen Difluoride, c) Sulfur Hexafluoride.

Step-by-step solution

Identify the elements in the compound

Look at each chemical formula and identify the elements present. For example:- \( \mathrm{XeF}_{2} \) contains Xenon (Xe) and Fluoride (F).- \( \mathrm{O}_{2} \mathrm{~F}_{2} \) contains Oxygen (O) and Fluorine (F).- \( \mathrm{SF}_{6} \) contains Sulfur (S) and Fluorine (F).

Determine the type of compound

Classify each compound as either a ionic or molecular compound. Given all compounds have nonmetals only, they are molecular compounds. These compounds use a specific set of rules for naming.

Name the compound using molecular compound rules

For molecular compounds, use prefixes to indicate the number of each type of atom.- In \(\mathrm{XeF}_{2}\), the prefix for two fluorine atoms is 'di'. Thus, the name is Xenon Difluoride.- In \( \mathrm{O}_{2} \mathrm{~F}_{2} \), two oxygen atoms is 'di' and two fluorine atoms is 'di'. Hence, the name of the compound is Dioxygen Difluoride.- In \( \mathrm{SF}_{6} \), the prefix for six fluorine atoms is 'hexa'. Therefore, the compound's name is Sulfur Hexafluoride.

Key concepts

Molecular Compounds

Molecular compounds are fascinating and are formed when two or more nonmetal elements combine chemically. This combination results in molecules, the smallest unit of a compound that retains its unique set of properties. Unlike ionic compounds, where metals and nonmetals interact through electrostatic forces, molecular compounds bond through shared electrons in covalent bonds. This sharing creates stable arrangements of atoms.
Molecular compounds can range from simple diatomic molecules, like oxygen \(\mathrm{O}_{2}\), to larger and more complex structures, like DNA. Though they often have lower melting and boiling points compared to ionic compounds, many molecular compounds are essential for life and technology.
Understanding that compounds are molecular is critical as it sets the stage for using specific naming rules (also known as chemical nomenclature) to determine their chemical formulas and names. When breaking down molecular compounds for naming, ensure that only nonmetals are present, as is the case in \(\mathrm{XeF}_{2}\), \(\mathrm{O}_{2} \mathrm{~F}_{2}\), and \(\mathrm{SF}_{6}\).

Chemical Formulas

Chemical formulas are the shorthand notation of chemistry that represents the composition of molecules. They give key insight into the types and ratios of atoms in a compound. Each element in a chemical formula is denoted by its chemical symbol, such as Xe for Xenon or F for Fluorine, and accompanied by a subscript indicating the number of atoms.

• The formula \(\mathrm{XeF}_{2}\) indicates one xenon atom and two fluorine atoms bonded to form a molecule.
• For \(\mathrm{O}_{2} \mathrm{~F}_{2}\), it conveys two oxygen atoms and two fluorine atoms in one molecule.
• The formula \(\mathrm{SF}_{6}\) shows one sulfur atom surrounded by six fluorine atoms.

When deciphering chemical formulas, it is vital to identify the elements and their respective number of atoms in the compound for the accurate derivation of its name using the proper nomenclature system. It serves as a bridge to understanding the structure and quantitative features of the compound.

Naming Rules

The naming rules for molecular compounds, or molecular nomenclature, provide a systematic way to name compounds based on the number of each type of atom present. These are predominantly governed by the use of prefixes to denote the number of atoms of each element.

• The prefix "mono-" means one, "di-" means two, "tri-" means three, "tetra-" means four, "penta-" means five, and "hexa-" means six, continuing up the numeric sequence.
• For example, in \(\mathrm{XeF}_{2}\), there are two fluorine atoms, so "di" is used, making the name 'Xenon Difluoride'.


• For \(\mathrm{O}_{2} \mathrm{~F}_{2}\), both elements have two atoms each, thus the name 'Dioxygen Difluoride'.


• In the case of \(\mathrm{SF}_{6}\), the six fluorine atoms imply the prefix "hexa", giving the name 'Sulfur Hexafluoride'.

This naming convention helps ensure clarity and precision, allowing scientists and chemists to communicate effectively about the myriad of compounds they work with. It's important to note that for the first element mentioned in the compound, the prefix "mono-" is usually omitted and only prefixes are used when necessary for both elements.