Question

Name the following compounds: (a) \(\mathrm{Fe}\left(\mathrm{ClO}_{3}\right)_{3}\), (b) \(\mathrm{HClO}_{2},(\mathrm{c}) \mathrm{XeF}_{6},(\mathrm{~d}) \mathrm{BrF}_{5},(\mathrm{e}) \mathrm{XeOF}_{4}\), (f) \(\mathrm{HIO}_{3}\) (named as an acid).

Short answer

(a) Iron(III) chlorate (b) Chlorous acid (c) Xenon hexafluoride (d) Bromine pentafluoride (e) Xenon oxytetrafluoride (f) Iodic acid

Step-by-step solution

Identify the type of compound

To name the given compounds correctly, we need to identify if they are ionic, covalent, or an acid. (a) \(\mathrm{Fe}\left(\mathrm{ClO}_{3}\right)_{3}\): This compound consists of the transition metal iron (Fe) and the polyatomic ion chlorate (ClO₃), which suggests it is an ionic compound. (b) \(\mathrm{HClO}_{2}\): This is an oxoacid, since it contains hydrogen, a non-metal (chlorine), and oxygen. (c) \(\mathrm{XeF}_{6}\): This is a covalent compound, as it contains two nonmetal elements. (d) \(\mathrm{BrF}_{5}\): This is also a covalent compound, with two nonmetals. (e) \(\mathrm{XeOF}_{4}\): Another covalent compound, with nonmetals only. (f) \(\mathrm{HIO}_{3}\): Like (b), this is an oxoacid, with hydrogen, a non-metal (iodine), and oxygen.

Naming ionic compounds

For ionic compounds, we name the cation (positively-charged ion) first and the anion second. The compound (a) is the only ionic compound present in this exercise. (a) \(\mathrm{Fe}\left(\mathrm{ClO}_{3}\right)_{3}\): The cation is iron (Fe), but we need to specify the oxidation state using Roman numerals in parentheses (e.g., Iron(II) or Iron(III)). To do this, we can use balancing the charges: Iron charge (Fe) = +x Chlorate charge (ClO₃) = -1 x 3 = -3 As the compound is electrically neutral, x - 3 = 0 → x = +3 Hence, the compound should be called Iron(III) chlorate.

Naming covalent compounds

For covalent compounds, we use prefixes to indicate the number of each element present, and end the name of the second element with "-ide". Here are the number prefixes: 1: mono, 2: di, 3: tri, 4: tetra, 5: penta, 6: hexa (c) \(\mathrm{XeF}_{6}\): The compound contains one xenon atom and six fluorine atoms. Thus, it should be named xenon hexafluoride. (d) \(\mathrm{BrF}_{5}\): The compound contains one bromine atom and five fluorine atoms. Thus, it should be named bromine pentafluoride. (e) \(\mathrm{XeOF}_{4}\): The compound contains one xenon atom, one oxygen atom, and four fluorine atoms. Thus, it should be named xenon oxytetrafluoride.

Naming oxoacids

Oxoacids are named based on the polyatomic anion they form with -ate or -ite ending. The anions with -ate ending become acid names with -ic suffix, while those with -ite ending become acid names with -ous suffix. Here are some examples: sulfate (SO₄²-) -> sulfuric acid; nitrite (NO₂⁻) -> nitrous acid (b) \(\mathrm{HClO}_{2}\): Removing the hydrogen, we get the anion ClO₂⁻, which is chlorite. Thus, the acid should be named chlorous acid. (f) \(\mathrm{HIO}_{3}\): Removing hydrogen, we get the anion IO₃⁻, which is iodate. Thus, the acid should be named iodic acid. The complete list of compound names is provided below: (a) Iron(III) chlorate (b) Chlorous acid (c) Xenon hexafluoride (d) Bromine pentafluoride (e) Xenon oxytetrafluoride (f) Iodic acid

Key concepts

Ionic Compounds

Ionic compounds are chemical compounds composed of ions held together by electrostatic forces known as ionic bonds. These compounds contain a metal and a non-metal. The metal loses electrons and becomes a positively charged cation, while the non-metal gains electrons, becoming a negatively charged anion. Naming these compounds involves naming the cation followed by the anion.

• The cation's name is typically the same as the element.
• The anion's name often ends with "-ide."
• If the metal can have different charges, like transition metals, indicate the charge with Roman numerals.

A classic example is (Fe(ClO₃)₃) , an ionic compound where iron (Fe) acts as the cation. Given the three chlorate ions (ClO₃⁻), each with a -1 charge, iron must have a +3 charge to balance the equation, forming Iron(III) chlorate.

Covalent Compounds

Covalent compounds are formed through the sharing of electrons between nonmetals. These compounds can comprise of two or more non-metal elements. Unlike ionic bonds, covalent bonds do not involve the transfer of electrons.

• Name covalent compounds by using prefixes to denote the number of atoms of each element.
• The suffix ".ide" is added to the name of the second element.
• Examples of prefixes include: mono-, di-, tri-, tetra-, penta-, and hexa-.

For instance, (XeF₆) is a covalent compound named xenon hexafluoride because it contains one xenon atom and six fluorine atoms. Similarly, (BrF₅) is named bromine pentafluoride because it includes five fluorine atoms bonded with a single bromine atom.

Oxoacids

Oxoacids are a specific type of acid that contains hydrogen, oxygen, and another element (usually a non-metal). The naming of oxoacids depends on the polyatomic anion they form and its suffix.

• "-ate" anions turn into "-ic" acids.
• "-ite" anions turn into "-ous" acids.

For example, (HClO₂) relates to the chlorite ion (ClO₂⁻); since the anion ends in "-ite," the acid is named chlorous acid. Similarly, (HIO₃) is derived from the iodate ion (IO₃⁻), and since it ends in "-ate," the resulting oxoacid is named iodic acid. By removing the hydrogen, the remaining negative ion determines the specific acid class.

Polyatomic Ions

Polyatomic ions consist of two or more atoms covalently bonded but carrying a net charge. These are critical in naming compounds since they often form the basis of ionic or complex ions in chemical formulas.

• Examples include chlorate (ClO₃⁻) and sulfate (SO₄²⁻).
• These ions sometimes contain oxygen, earning names based on the number of oxygen atoms.
• "Per-...-ate" indicates more oxygen compared to the "-ate" form.
• "Hypo-...-ite" indicates fewer oxygen atoms compared to the "-ite" form.

For example, in the compound (Fe(ClO₃)₃) , the polyatomic ion is chlorate. Despite being a single ion, its recognition and understanding are crucial for properly naming the ionic compound, resulting in Iron(III) chlorate.