Question

Name the following compounds: (a) \(\mathrm{S}_{2} \mathrm{Cl}_{2}\) (b) ICl (c) \(\mathrm{ICl}_{3}\)

Short answer

(a) Disulfur Dichloride (b) Iodine Chloride (c) Iodine Trichloride

Step-by-step solution

Understand the Molecular Compound Naming Rules

Molecular compounds consist of non-metals. We use prefixes to denote the number of each type of atom in the compound, such as mono-, di-, tri-, etc. For two-element compounds, the first element's name remains unchanged, while the second element's name is modified to end in '-ide.'

Naming \\({\mathrm{S}}_{2}{\mathrm{Cl}}_{2}\\)

This compound is composed of two sulfur atoms and two chlorine atoms. Using the naming rules, it is called Disulfur Dichloride. The prefix 'di-' indicates two atoms of sulfur and 'dichloride' refers to two atoms of chlorine.

Naming \\({\mathrm{ICl}}\\)

The compound consists of one iodine atom and one chlorine atom. The prefix 'mono-' is typically omitted for the first element. Therefore, this compound is named Iodine Chloride.

Naming \\({\mathrm{ICl}}_{3}\\)

Containing one iodine atom and three chlorine atoms, this compound is named Iodine Trichloride. The absence of the prefix for iodine indicates a single atom, while 'tri-' indicates three chlorine atoms.

Key concepts

Chemical Nomenclature

Chemical nomenclature is the system of rules and conventions used to name chemical compounds systematically. It ensures that there is a universal way of identifying substances. Nomenclature involves understanding the structure of molecules and using the proper prefixes and suffixes to denote the compound’s composition. The goal is to provide a clear and concise name that reflects the chemical’s character and number of atoms involved. In molecular compounds, which consist of two or more non-metal elements, the rules are slightly different from ionic compounds. The first element in the compound retains its elemental name, whereas the second element's name is altered to end with '-ide.' The exact number of each atom type is denoted with specific prefixes that help identify the ratio of elements within the compound structure.

Molecular Compounds

Molecular compounds are chemical compounds formed from non-metal atoms. These compounds are characterized by covalent bonding, where atoms share electrons to achieve stable electron configurations. Molecular compounds can consist of two or more different elements. For example, in the given exercises, compounds like \(\mathrm{S}_{2}\mathrm{Cl}_{2}\), ICl, and \(\mathrm{ICl}_{3}\) show how these non-metal atoms combine in specific ratios. Here are some characteristics of molecular compounds:

• Composed of non-metals
• Involve covalent bonds
• Tend to have low melting and boiling points compared to ionic compounds
• Are usually not conductors of electricity in solid or liquid state

Naming molecular compounds requires understanding each element’s role and bond within the molecule, and indicating the number of each atom through prefixes.

Prefixes in Chemistry

Prefixes are integral to naming molecular compounds, as they indicate the number of atoms of each element present. These prefixes replace numerical notation to provide a more readable name. Here is a list of common prefixes used in molecular nomenclature:

• Mono-: 1 (often omitted for the first element)
• Di-: 2
• Tri-: 3
• Tetra-: 4
• Penta-: 5
• Hexa-: 6
• Hepta-: 7
• Octa-: 8
• Nona-: 9
• Deca-: 10

The use of these prefixes helps convey the exact numerical formula of a compound, making it easier to understand its composition. For example, in the compound \(\mathrm{S}_{2}\mathrm{Cl}_{2}\), 'di-' is used because there are two sulfur atoms and two chlorine atoms, resulting in the name Disulfur Dichloride. These prefixes are essential for maintaining clarity in chemical communication.