Question

Name the following binary compounds: (a) \(\mathrm{PI}_{3}\) (b) \(\mathrm{AsCl}_{3}\) (c) \(\mathrm{P}_{4} \mathrm{~S}_{3}\) (d) \(\mathrm{Al}_{2} \mathrm{~F}_{6}\) (e) \(\mathrm{N}_{2} \mathrm{O}_{5}\) (f) \(\mathrm{AsCl}_{5}\)

Short answer

(a) phosphorus triiodide, (b) arsenic trichloride, (c) tetraphosphorus trisulfide, (d) aluminum fluoride, (e) dinitrogen pentoxide, (f) arsenic pentachloride.

Step-by-step solution

Understanding Binary Compounds

Binary compounds are composed of two different elements. For naming, we typically use the full element name for the first element and the root of the second element followed by the suffix '-ide'. Prefixes (mono-, di-, tri-, etc.) indicate the number of atoms.

Naming PI3

For PI3, 'P' is phosphorus and 'I' is iodine. The compound is named 'phosphorus triiodide', using 'tri-' to indicate three iodine atoms.

Naming AsCl3

In AsCl3, 'As' is arsenic and 'Cl' represents chlorine. The compound is called 'arsenic trichloride', using 'tri-' for the three chlorine atoms.

Naming P4S3

P4S3 includes phosphorus (P) and sulfur (S). The name is 'tetraphosphorus trisulfide', where 'tetra-' signifies four phosphorus atoms and 'tri-' indicates three sulfur atoms.

Naming Al2F6

Al2F6 has aluminum and fluorine elements. It's known as 'aluminum fluoride', as this compound is typically referred to by this conventional name (its simplest form is AlF3).

Naming N2O5

For N2O5, it contains nitrogen and oxygen. It is named 'dinitrogen pentoxide', where 'di-' and 'penta-' denote two nitrogen and five oxygen atoms, respectively.

Naming AsCl5

AsCl5 consists of arsenic and chlorine. The name is 'arsenic pentachloride', using 'penta-' to indicate five chlorine atoms.

Key concepts

Binary Compounds

Binary compounds are chemical substances that consist of exactly two different elements. This simplicity makes them a great starting point for learning chemical nomenclature. When we name binary compounds, we focus on the two elements involved and their respective quantities within the compound.

• The first element in the compound is named using its full elemental name.
• The second element, however, uses the root of its name combined with the suffix '-ide'.
• To indicate the quantity of each type of atom, prefixes such as mono- (1), di- (2), tri- (3), tetra- (4), penta- (5), etc., are utilized.

In this exercise, you have examples like \( \mathrm{PI}_{3} \), which is named phosphorus triiodide, highlighting three iodine atoms in compound form.

Chemical Formulas

Chemical formulas are symbolic representations of molecules that detail the elements present and their ratios within the compound. Each chemical formula gives valuable information:

• The letters represent the element symbols derived from the periodic table.
• Subscripts following each element symbol convey the number of atoms of that element in one molecule of the compound.

For example, in \( \mathrm{N}_{2} \mathrm{O}_{5} \), the formula tells us there are two nitrogen atoms and five oxygen atoms in each molecule. This structural insight is fundamental in determining compound names and understanding their composition.

Systematic Naming

Systematic naming is a standardized method used in chemistry to name chemical compounds. This ensures consistency and clarity across scientific communications.

• Names start with the more positive or electropositive element, which is generally written first in the formula.
• The second, more electronegative element takes on the '-ide' suffix, and the number of atoms is indicated by prefixes.

In cases such as \( \mathrm{AsCl}_{3} \), we start with arsenic and then describe the chlorine atoms with 'trichloride'. This system allows chemists around the world to understand exactly what compound is being referenced.

Inorganic Chemistry

Inorganic chemistry deals with the properties and behavior of inorganic compounds, which encompass all substances not covered by organic chemistry. These include metals, minerals, and organometallics, as well as the binary compounds featured in our exercise.

• Many binary compounds, like \( \mathrm{Al}_{2} \mathrm{F}_{6} \), are often seen in inorganic chemistry. They illustrate the interactions between metallic and non-metallic elements.
• Inorganic chemistry provides the basis for understanding these compounds' roles, uses, and reactions.

Understanding binary compounds and systematic naming aids greatly in exploring the vast field of inorganic chemistry, setting a foundation for more complex studies.