Question

Name each of the following compounds: a. Cul b. \(\mathrm{CuI}_{2}\) c. \(\mathrm{CoI}_{2}\) d. \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) e. \(\mathrm{NaHCO}_{3}\) \(\mathbf{f .} \mathrm{S}_{4} \mathrm{N}_{4}\) g. \(\mathrm{SF}_{4}\) h. NaOCl i. \(\mathrm{BaCrO}_{4}\) J. \(\mathrm{NH}_{4} \mathrm{NO}_{3}\)

Short answer

a. Copper(I) Iodide b. Copper(II) Iodide c. Cobalt(II) Iodide d. Sodium Carbonate e. Sodium Bicarbonate f. Tetrasulfur Tetranitride g. Sulfur Tetrafluoride h. Sodium Hypochlorite i. Barium Chromate j. Ammonium Nitrate

Step-by-step solution

a. CuI

This is a binary ionic compound composed of Copper (Cu) and Iodine (I). Since Copper is a transition metal, we must indicate its charge with a Roman numeral. Copper has a charge of +1 in this compound, and Iodine has a charge of -1. The name of this compound is Copper(I) Iodide.

b. \(\mathrm{CuI}_{2}\)

In this compound, Copper (Cu) has a charge of +2, while Iodine (I) has a charge of -1. The name of this compound is Copper(II) Iodide.

c. \(\mathrm{CoI}_{2}\)

Here, we have the transition metal Cobalt (Co) with a charge of +2 and Iodine (I) with a charge of -1. The compound's name is Cobalt(II) Iodide.

d. \(\mathrm{Na}_{2} \mathrm{CO}_{3}\)

This compound consists of the Sodium ion (Na) with a charge of +1 and the polyatomic ion Carbonate (CO\(_{3}\)) with a charge of -2. The name of this compound is Sodium Carbonate.

e. \(\mathrm{NaHCO}_{3}\)

This compound is composed of Sodium (Na) with a charge of +1 and the polyatomic ion Hydrogen Carbonate (HCO\(_{3}\)) with a charge of -1, also known as Bicarbonate. The name of this compound is Sodium Bicarbonate.

f. \(\mathrm{S}_{4}\mathrm{N}_{4}\)

This compound is a binary covalent compound consisting of Sulfur (S) and Nitrogen (N). The prefixes for 4 are "tetra." So, the name of this compound is Tetrasulfur Tetranitride.

g. \(\mathrm{SF}_{4}\)

This is a covalent compound composed of one Sulfur (S) atom and four Fluorine (F) atoms. The prefix for 4 is "tetra." The name of this compound is Sulfur Tetrafluoride.

h. NaOCl

This compound has Sodium (Na) and the polyatomic ion Hypochlorite (OCl). The name of this compound is Sodium Hypochlorite.

i. \(\mathrm{BaCrO}_{4}\)

In this ionic compound, we have Barium (Ba) and the polyatomic ion Chromate (CrO\(_{4}\)). The name of this compound is Barium Chromate.

j. \(\mathrm{NH}_{4}\mathrm{NO}_{3}\)

This compound contains the polyatomic ion Ammonium (NH\(_{4}\)) and the polyatomic ion Nitrate (NO\(_{3}\)). The name of this compound is Ammonium Nitrate.

Key concepts

Binary Ionic Compounds

Binary ionic compounds consist of two different elements: typically, one metal and one non-metal. The metal donates electrons to become a positively charged ion (cation), while the non-metal accepts electrons to become a negatively charged ion (anion). These compounds are named by writing the cation's name first, followed by the anion's name with its end altered to '-ide'.

For example, NaCl is a binary ionic compound composed of sodium (Na) and chlorine (Cl). Its name, Sodium Chloride, reflects the elements involved with the -ide ending to indicate the single anion.

When naming compounds like CuI, identifying the charge of the cation is crucial, especially when it involves a transition metal, which can have multiple possible charges. To communicate the cation's specific charge, Roman numerals are used. Thus, CuI is named Copper(I) Iodide, signifying that copper has a +1 charge in this compound.

Polyatomic Ions

Polyatomic ions are charged entities composed of two or more atoms covalently bonded together, or of a metal complex that acts as a single unit. These ions have a charge because they contain a total number of electrons that is either more or less than the total number of protons in the atoms. To name compounds containing polyatomic ions, you simply state the cation followed by the name of the polyatomic ion.

For instance, in Na₂CO₃, Na represents the Sodium cation, and CO₃ is the Carbonate anion, a common polyatomic ion. Therefore, this compound's name is Sodium Carbonate. Another example is NH₄NO₃, where NH₄ is the Ammonium cation and NO₃ is the Nitrate anion, resulting in the name Ammonium Nitrate.

Transition Metals

Transition metals are elements found in the central block of the periodic table (groups 3-12). They are characterized by their ability to form compounds with variable oxidation states, which significantly influences the naming of compounds they form. The variable charges of transition metals require the use of Roman numerals in compound naming to indicate the metal's specific charge in that compound.

As we see in compounds such as CuI₂ and CoI₂, we must specify that Copper has a +2 oxidation state and Cobalt has a +2 oxidation state, resulting in the names Copper(II) Iodide and Cobalt(II) Iodide. This clarity is essential because these metals can exhibit different charges, which directly affect the stoichiometry and chemistry of the compounds they form.