Question

Give a systematic name for each of the following binary molecular compounds: (a) \(\mathrm{BrCl}\) (b) \(\mathrm{SF}_{6}\) (c) \(\mathrm{I}_{4} \mathrm{O}_{9}\) (d) \(\mathrm{Cl}_{2} \mathrm{O}_{7}\)

Short answer

(a) Bromine monochloride, (b) Sulfur hexafluoride, (c) Tetraiodine nonaoxide, (d) Dichlorine heptoxide.

Step-by-step solution

Understanding Binary Molecular Compounds

Binary molecular compounds are composed of two different nonmetal elements. They are named using a prefix system to indicate the number of each type of atom, followed by the name of each element.

Naming the First Element

For each compound, name the first element as it appears on the periodic table. No prefix is used if there is only one atom of the first element. If there are multiple atoms, use the appropriate prefix (mono- is not used for the first element).

Naming the Second Element

The second element in the compound is named with the appropriate prefix based on the number of atoms it has, followed by the root of the element's name and the suffix "-ide."

Applying the Rules to Compound (a): BrCl

(a) For BrCl, the first element is bromine and the second is chlorine. Since there is one atom of each, bromine is named without a prefix, and chlorine is prefixed with 'mono-'. Therefore, the name is bromine monochloride.

Applying the Rules to Compound (b): SF6

(b) For SF6, the first element is sulfur and there is one atom of sulfur, so it is named without a prefix. The second element is fluorine with six atoms, so it is named hexafluoride. Therefore, the name is sulfur hexafluoride.

Applying the Rules to Compound (c): I4O9

(c) For I4O9, the first element is iodine with four atoms, so it is named tetraiodine. The second element is oxygen with nine atoms, so it is named nonaoxide. Therefore, the name is tetraiodine nonaoxide.

Applying the Rules to Compound (d): Cl2O7

(d) For Cl2O7, the first element is chlorine with two atoms, so it is named dichlorine. The second element is oxygen with seven atoms, so it is named heptoxide. Therefore, the name is dichlorine heptoxide.

Key concepts

Systematic Naming of Compounds

Systematic naming is an essential part of understanding and communicating chemical compounds clearly and accurately. By using a consistent set of rules, chemists ensure that each compound has one unique name. This helps prevent confusion and ensures that scientists around the world can understand each other.
When dealing with binary molecular compounds, systematic naming entails a sequence of steps to derive the correct name. The process begins with identifying the two nonmetal elements involved. From there, you follow specific naming conventions which involve using prefixes to denote the number of atoms present. This prevents ambiguity.
Applying systematic naming to

• BrCl involves recognizing bromine and chlorine. Since both have one atom each, bromine is named plainly and chlorine is prefixed with 'mono-', forming bromine monochloride.
• SF extsubscript{6} features sulfur and fluorine, calling it sulfur hexafluoride due to the six fluorine atoms.

The Prefix System for Molecular Compounds

The prefix system is fundamental in the naming of binary molecular compounds. This method uses specific prefixes derived from Greek or Latin to indicate the number of atoms of each element in the compound. These prefixes are globally recognized and easily learned, making them user-friendly for students and professionals alike.
Here's a quick reference guide for prefixes based on the number of atoms:

• 1 - mono-
• 2 - di-
• 3 - tri-
• 4 - tetra-
• 5 - penta-
• 6 - hexa-
• 7 - hepta-
• 8 - octa-
• 9 - nona-
• 10 - deca-

Use of these prefixes is critical to accurately convey the number of atoms, as seen in compounds like I extsubscript{4}O extsubscript{9} (tetraiodine nonaoxide) and Cl extsubscript{2}O extsubscript{7} (dichlorine heptoxide). It's crucial to remember that 'mono-' is omitted for the first element.

Understanding Nonmetal Elements in Naming

In binary molecular compounds, only nonmetals are involved. Nonmetals are elements that typically gain electrons during chemical reactions and form covalent bonds with other nonmetals. They are found on the right side of the periodic table, starting with carbon and moving to noble gases.
These elements can form a variety of compounds because they share electrons with each other. Understanding the properties and typical behaviors of nonmetals is important for chemists as they name and understand compounds.

• The tendency of nonmetals to form covalent bonds allows them to stabilize by achieving full electron shells.
• Examples include oxygen, nitrogen, chlorine, and sulfur.

In systematic naming, the correct identification of nonmetal elements is crucial since it affects the naming order and the corresponding prefixes.

Chemical Nomenclature Explained

Chemical nomenclature is the set of rules used to generate systematic names for chemical compounds. This system is a part of chemical communication essential for scientists and students alike.
It involves different naming conventions depending on the types of compounds:

• IUPAC Nomenclature is standardized and provides a universal language for chemistry.
• In regards to binary molecular compounds, it ensures concise and correct naming.

A consistent chemical nomenclature guides chemists in understanding the composition and structure of compounds, and it is vital for effective scientific communication. Using chemical nomenclature helps prevent misunderstandings resulting from common names and allows chemists to derive the formula of a compound just by reading its name. Recognizing compounds like SF extsubscript{6} as sulfur hexafluoride illustrates the power of this system.