Question

Name the following compounds and assign oxidation states to the halogens in them: (a) \(\mathrm{KClO}_{3},\) (b) \(\mathrm{Ca}\left(\mathrm{IO}_{3}\right)_{2}\) ,\((\mathbf{c}) \mathrm{AlCl}_{3},(\mathbf{d}) \mathrm{HBrO}_{3},(\mathbf{e}) \mathrm{H}_{5} \mathrm{IO}_{6},(\mathbf{f}) \mathrm{XeF}_{4}\)

Short answer

The names of the given compounds and the oxidation states of the halogens in them are: a) Potassium chlorate (Cl: +5) b) Calcium iodate (I: +5) c) Aluminum chloride (Cl: -1) d) Bromic acid (Br: +5) e) Iodic acid (I: +7) f) Xenon tetrafluoride (F: -1)

Step-by-step solution

Identify the halogen in each compound

In each compound, look for the element belonging to the group 17 of the periodic table: chlorine (Cl), iodine (I), bromine (Br), or fluorine (F). In each of the given compounds, the halogen present is - a) Cl b) I c) Cl d) Br e) I f) F

Assign oxidation states to halogens

For each compound, assign oxidation states to the halogens using the rules of assigning oxidation numbers: a) KClO3: In KClO3, the oxidation state of Cl is +5. b) Ca(IO3)2: In Ca(IO3)2, the oxidation state of I is +5. c) AlCl3: In AlCl3, the oxidation state of Cl is -1. d) HBrO3: In HBrO3, the oxidation state of Br is +5. e) H5IO6: In H5IO6, the oxidation state of I is +7. f) XeF4: In XeF4, the oxidation state of F is -1.

Name the compounds

Applying the IUPAC nomenclature rules, we can name the given compounds as follows: a) KClO3: Potassium chlorate b) Ca(IO3)2: Calcium iodate c) AlCl3: Aluminum chloride d) HBrO3: Bromic acid e) H5IO6: Iodic acid f) XeF4: Xenon tetrafluoride

Key concepts

Naming Chemical Compounds

Understanding how to name chemical compounds is essential to communicate clearly in the field of chemistry. The International Union of Pure and Applied Chemistry (IUPAC) provides specific guidelines to ensure that each compound has a unique and universally accepted name.

For simple binary ionic compounds, such as \textbf{AlCl}\(_3\) (aluminum chloride), the name comprises the metal's name (aluminum) followed by the non-metal's name altered to end in '-ide' (chloride). For molecular compounds that contain polyatomic ions like \textbf{KClO}\(_3\) (potassium chlorate) or \textbf{Ca(IO}\(_3)_2\) (calcium iodate), the name of the cation (potassium, calcium) is followed by the name of the polyatomic anion (chlorate, iodate).

In cases involving acids, such as \textbf{HBrO}\(_3\) (bromic acid) and \textbf{H}\(_5\)\textbf{IO}\(_6\) (iodic acid), the name typically reflects the acidity and the state of oxidation of the central non-metal atom. Lastly, compounds with noble gases, like \textbf{XeF}\(_4\) (xenon tetrafluoride), follow a naming pattern where the name of the noble gas is followed by the mono-, di-, tri-, tetra-, etc. prefix that corresponds to the number of atoms of the other element.

Rules for Assigning Oxidation Numbers

Assigning oxidation numbers (also called oxidation states) is a fundamental concept for balancing chemical equations and understanding redox reactions. The rules for determining oxidation states are hierarchical:

• The oxidation number of atoms in their elemental form is zero.
• For monoatomic ions, the oxidation number is equal to the charge on the ion.
• Oxygen usually has an oxidation number of -2, except in peroxides or when bonded to fluorine.
• Hydrogen is usually +1 except when bonded to metals in metal hydrides where it is -1.
• The sum of the oxidation numbers in a neutral compound is zero, and in a polyatomic ion, it equals the charge of the ion.

By applying these rules, you systematically determine the oxidation states of elements in a compound. For example, in \textbf{KClO}\(_3\), potassium (K) holds a +1 charge, and oxygen (O) typically has an oxidation number of -2. There are three oxygen atoms, contributing a total of -6. To balance the -6 charge with potassium's +1, chlorine (Cl) must have an oxidation number of +5.

Group 17 Elements Chemistry

The group 17 elements, also known as halogens, are a fascinating part of the periodic table with unique properties and consistent patterns in their chemistry. They include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

These non-metals are highly reactive, particularly fluorine, which is the most reactive of all elements. Halogens readily form compounds with metals and non-metals alike. They typically exhibit a range of oxidation states, like -1 in \textbf{AlCl}\(_3\) where chlorine pairs with a metal, or positive states such as +5 in \textbf{ClO}\(_3\)^- or +7 in \textbf{H}\(_5\)\textbf{IO}\(_6\), when involved in oxyanions or oxoacids.

Their reactivity is due to their electron configurations; they have seven electrons in their outer shell and require one more electron to achieve a stable noble gas configuration. This drives them to gain electrons in reactions, which is the key to their role in redox processes.

IUPAC Nomenclature

The IUPAC nomenclature system standardizes the naming of chemical compounds to avoid confusion and ensure that every compound has a clear, globally recognized name. It involves a series of rules that provide details on naming various organic and inorganic compounds.

Inorganic nomenclature includes naming ionic compounds, molecular compounds, acids, and coordination compounds. The system uses prefixes and suffixes to indicate the types and numbers of atoms present. For example, the 'ate' suffix in \textbf{potassium chlorate} (\textbf{KClO}\(_3\)) signifies that it is an oxyanion of chlorine in a higher oxidation state.

Organic nomenclature, meanwhile, is more complex due to the vast diversity of organic compounds. It considers the longest carbon chain, functional groups, and positions of the substituents to determine the compound's name. Understanding both organic and inorganic naming rules is essential for students to navigate the intricate world of chemical compound names effectively.