Question

Simple Lewis Structures, Formulas, and Names fo Write a formula for each molecular compound. $$ \begin{array}{ll}{\text { a. boron tribromide }} & {\text { b. dichlorine monoxid }} \\ {\text { c. }} {\text { xenon tetrafluoride }} & {\text { d. carbon tetrabromid }}\end{array} $$

Short answer

a. BBr3, b. Cl2O, c. XeF4, d. CBr4

Step-by-step solution

Identify the Elements Involved

Examine each name to identify the elements involved and note their chemical symbols. For boron tribromide, boron (B) and bromine (Br) are present. In dichlorine monoxide, chlorine (Cl) and oxygen (O) are the elements. Xenon tetrafluoride includes xenon (Xe) and fluorine (F), and carbon tetrabromide has carbon (C) and bromine (Br).

Determine the Number of Atoms

Determine the number of atoms of each element in the compound using prefixes. The prefix 'tri' means three, 'di' indicates two, 'mono' means one, 'tetra' implies four, and 'tetr' also means four. Match these prefixes with the number of atoms they represent for each element.

Write the Formulas

Combine the symbols and their corresponding numbers of atoms to form the chemical formula. For boron tribromide, write B with three Br atoms, giving BBr3, which denotes one B atom and three Br atoms. Follow the same pattern for other compounds.

Key concepts

Chemical Formulas

Chemical formulas are essential tools in chemistry, providing a concise method for representing the composition of molecules and compounds. They consist of the element symbols from the periodic table and numerical subscripts indicating the number of atoms of each element present in the molecule.

For example, to write the chemical formula for boron tribromide, we identify the elements involved – boron (B) and bromine (Br) – and use the prefix 'tri-', which tells us there are three bromine atoms. Therefore, the formula is written as BBr₃.

When analyzing the chemical formula, it's crucial to understand these prefixes, as they are the bridge between the compound's name and its chemical composition. This connection allows us to visualize the makeup of the compound at a molecular level, underlining the importance of accuracy in chemical formulas.

It's also vital to remember that the subscripts in a chemical formula should only be used when there is more than one atom of a particular element. If only one atom is present, no subscript is used, as seen in the name 'carbon monoxide,' which is correctly written as CO, not C₁O₁.

Naming Molecular Compounds

The naming of molecular compounds follows specific rules that help convey the structure and composition of the compound through its name. These rules involve using prefixes to indicate the number of atoms and choosing the appropriate suffixes and endings to reflect the compound's nature.

Consider the compound 'dichlorine monoxide.' 'Di-' indicates the presence of two chlorine atoms, and 'mono-' indicates a single oxygen atom. Thus, the name of the compound itself provides insight into its composition.

One common area of confusion for students involves the prefix 'mono-'. It's important to note that 'mono-' is often omitted when it applies to the first element in the compound's name but is used for the second when there is only one atom of that element. For instance, 'carbon monoxide' is not called 'monocarbon monoxide' because 'mono-' is assumed for the first element if no other prefix is present.

A solid grasp of these naming conventions is crucial for any student of chemistry, as it enables clear communication and understanding of chemical compositions. By familiarizing oneself with the prefixes and their meanings, as well as their proper application, confidence in naming molecular compounds is achieved.

Chemical Nomenclature

Chemical nomenclature is the standardized system used for naming chemical substances. Every compound has a unique name that tells chemists a lot about its structure and components. This system is universal and has been agreed upon by international bodies to ensure consistency and clarity in the field of chemistry.

There are different nomenclature systems for different types of compounds, but all aim to provide a full and unambiguous descriptor. For instance, ionic compounds, covalent compounds, and acids each have distinct naming rules. In the case of xenon tetrafluoride from the exercise, the name signifies a covalent compound consisting of xenon (Xe) and four atoms of fluorine (F), resulting in the formula XeF₄.

To achieve proficiency in chemical nomenclature, one must study and understand the different rules and exceptions involved. This includes the use of specific prefixes for numbers, the usage of Greek prefixes for binary nonmetals, and learning the correct order in which the components of a compound should be named. Mastery of chemical nomenclature not only provides better understanding of chemistry but also enables accurate and effective communication within the scientific community.