Question

Write the name of each of the following binary compounds of nonmetallic elements. a. \(\mathrm{KrF}_{2}\) b. \(\mathrm{Se}_{2} \mathrm{~S}_{6}\) c. \(\mathrm{AsH}_{3}\) d. \(\mathrm{XeO}_{4}\) e. \(\mathrm{BrF}_{3}\) f. \(P_{2} S_{5}\)

Short answer

a. Krypton Difluoride (KrF₂) b. Diselenium Hexasulfide (Se₂S₆) c. Arsenic Trihydride (AsH₃) d. Xenon Tetroxide (XeO₄) e. Bromine Trifluoride (BrF₃) f. Diphosphorus Pentasulfide (P₂S₅)

Step-by-step solution

a. Krypton Fluoride (KrF₂)

The first element of this compound is krypton (Kr) and the second one is fluorine (F). When naming this compound, we write the name of krypton first and then the name of fluorine. Since there are two fluorine atoms in the compound, we add the prefix "di" in front of "fluoride." So the name of the compound is Krypton Difluoride.

b. Selenium Sulfide (Se₂S₆)

The first element in this compound is selenium (Se) and the second element is sulfur (S). We name the first element (Selenium) and then the second one (Sulfur). To indicate the number of atoms in each element, we use prefixes. Here there are 2 selenium atoms and 6 sulfur atoms, so the compound's name is Diselenium Hexa(sulfide).

c. Arsenic Hydride (AsH₃)

The first element in this compound is arsenic (As) and the second one is hydrogen (H). We name the first element (Arsenic) and then the second one (Hydride). There are 3 hydrogen atoms, so the compound's name is Arsenic Trihydride.

d. Xenon Oxide (XeO₄)

The first element in this compound is xenon (Xe) and the second one is oxygen(O). We name the first element (Xenon) and then the second one (Oxide). There are 4 oxygen atoms, so the compound's name is Xenon Tetroxide.

e. Bromine Fluoride (BrF₃)

The first element in this compound is bromine (Br) and the second one is fluorine (F). We name the first element (Bromine) and then the second one (Fluoride). There are 3 fluorine atoms, so the compound's name is Bromine Trifluoride.

f. Phosphorus Sulfide (P₂S₅)

The first element in this compound is phosphorus (P) and the second one is sulfur (S). We name the first element (Phosphorus) and then the second one (Sulfide). To show the number of atoms in each element, we use the prefixes. There are 2 phosphorus atoms and 5 sulfur atoms, so the compound's name is Diphosphorus Pentasulfide.

Key concepts

Binary Compounds

Binary compounds are chemical substances that consist of exactly two different elements. Elements that form a binary compound are usually a combination of a metal with a nonmetal, or two nonmetals, as seen in the given exercise with compounds like Krypton Difluoride and Arsenic Trihydride. Understanding binary compounds is critical because they are among the simplest compounds and hence form the basis for understanding more complex chemical substances.

For students starting to learn about chemical nomenclature, it's essential to recognize binary compounds because the rules for naming them are relatively straightforward. Each binary compound's name reflects the elements involved, and when nonmetals combine to form a binary compound, as in these exercise examples, they often form molecular compounds, which means they share electrons (covalent bonding).

Chemical Formulas

Chemical formulas represent the composition of a substance using the symbols for the elements and numerical subscripts to show the ratio of atoms. In the exercises provided, for instance, the chemical formula \(\mathrm{KrF}_{2}\) represents a compound with one atom of krypton (Kr) and two atoms of fluorine (F).

Chemical formulas are not just symbolic representations; they convey a lot of information. They can tell us the exact number of each type of atom in a compound and, by extension, the relative masses. This information is crucial for calculating molecular weights, understanding chemical reactions, and stoichiometry. When you're approaching problems involving chemical formulas, it's helpful to first identify the elements involved and then count the number of atoms of each to better understand the compound's properties.

Prefixes in Chemical Names

Prefixes in chemical names provide a systematic way to describe the number of atoms of each element in a compound. They are essential in the nomenclature of molecular compounds, particularly for nonmetals where the number of atoms needs to be explicitly stated. For instance, 'mono-' indicates one, 'di-' indicates two, 'tri-' signifies three, and this pattern continues with 'tetra-' for four, 'penta-' for five, up to 'deca-' for ten.

In the exercise solutions, these prefixes are used to clarify how many atoms of each element are present in the compound. For example, Diphosphorus Pentasulfide (\(P_{2}S_{5}\)) highlights the presence of two phosphorus atoms and five sulfur atoms. Learning and correctly using these prefixes are vital because it can change the meaning and the actual substance being referred to. Never skip the prefix for the first element if the number is one, except when that element is oxygen, in which case the prefix is often dropped to avoid awkward pronunciation.