Question

Supply a Stock system name for each of the following ternary ionic compounds: (a) \(\mathrm{CuSO}_{4}\) (b) \(\mathrm{FeCrO}_{4}\) (c) \(\mathrm{Hg}\left(\mathrm{NO}_{2}\right)_{2}\) (d) \(\mathrm{Pb}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}\)

Short answer

(a) Copper (II) sulfate, (b) Iron (II) chromate, (c) Mercury (II) nitrite, (d) Lead (II) acetate.

Step-by-step solution

Determine the charge on the metal

In these ternary ionic compounds, the metal can have different oxidation states. Determine the charge of the polyatomic ion and balance it with the known charge of the metal to find the metal's oxidation state.

Assign the Stock system name

Use the oxidation state determined in Step 1 to assign the Stock system name for each compound by indicating the charge of the metal in Roman numerals within parentheses.

Apply to 6CuSO_{4}7

Copper sulfate 6(7CuSO_{4}) is composed of Cu and SO₄²⁻. Since SO₄ has a charge of -2 and the compound is neutral, Cu must be 6+27 to balance it. Name: Copper (II) sulfate.

Apply to 6FeCrO_{4}7

In Iron chromate (6FeCrO_{4}7), CrO₄ has a charge of -2. To balance, Fe must be 6+27. Name: Iron (II) chromate.

Apply to 6Hg ext{(NO}_{2} ext{)}_{2}7

Mercury nitrite, 6Hg ext{(NO}_{2} ext{)}_{2}7, involves (NO₂⁻) which has a charge of -1. With 2 6NO₂⁻7 ions, the total negative charge is -2, indicating that Hg is 6+27. Name: Mercury (II) nitrite.

Apply to 6Pb ext{(C}_{2} ext{H}_{3} ext{O}_{2} ext{)}_{2}7

Lead acetate 6Pb ext{(C}_{2} ext{H}_{3} ext{O}_{2} ext{)}_{2}7 involves the acetate ion (C₂H₃O₂⁻) with a charge of -1. Two acetate ions give a total charge of -2, meaning Pb must be 6+27. Name: Lead (II) acetate.

Key concepts

Ternary Ionic Compounds

Ternary ionic compounds are fascinating chemical substances that consist of three different elements. These compounds usually include a metal and a polyatomic ion. What makes them unique is their combination of more than two types of atoms, which contribute to a wide array of chemical properties and applications.

For example, in the compound formula \(\mathrm{CuSO}_{4}\) (Copper sulfate), three elements are involved: copper (Cu), sulfur (S), and oxygen (O), with the sulfate ion (\(\mathrm{SO}_{4}^{2-}\)) acting as the polyatomic component. This combination is typical among ternary ionic compounds, which often involve complex ions that bring together several atomic groups into a single charge entity. These complex ions are pivotal in determining the compound's structure and reactivity.

Understanding ternary ionic compounds is crucial for unraveling the world of inorganic chemistry and mastering the synthesis and naming of complex materials.

Oxidation States

Oxidation states are fundamental to identifying and naming compounds. An oxidation state, often referred to as oxidation number, indicates the degree of oxidation—or loss of electrons—of an element within a compound. This numeric representation is vital for recognizing how electrons are distributed among the atoms in a chemical entity.

In any given compound, the oxidation state helps balance the electrical charges. For instance, in the compound \(\mathrm{CuSO}_{4}\), copper (Cu) must have an oxidation state of +2 to balance the \(\mathrm{SO}_{4}^{2-}\)'s charge of -2, resulting in a neutral compound.

Identifying oxidation states is a step-by-step process:

• First, recognize the charge of the polyatomic ion or individual ions involved.
• Next, calculate the necessary state for the metal to achieve electrical neutrality in the compound.

Properly understanding oxidation states is crucial for determining the correct Stock system name when dealing with compounds in chemistry.

Polyatomic Ions

Polyatomic ions are groups of atoms covalently bonded together, which carry a charge and act as a single entity in compounds. These ions are fundamental components in many ionic compounds and drive the variety of chemistries these substances exhibit.

Several common polyatomic ions, such as \(\mathrm{SO}_{4}^{2-}\) (sulfate), \(\mathrm{CrO}_{4}^{2-}\) (chromate), and \(\mathrm{NO}_{2}^{-}\) (nitrite), frequently form compounds with metals and continuously participate in chemical reactions.

These ions are unique because:

• They contain multiple atoms bonded together yet function as one single charged entity.
• They are involved in several chemical reactions, including precipitation, acid-base, and redox reactions.

Polyatomic ions are the puzzle pieces of chemistry that tie together various elements into functional compounds, influencing both their naming and behavior.

Chemical Nomenclature

Chemical nomenclature is the set of rules and conventions used to name chemical substances. It ensures consistency and clarity in identifying compounds, which is crucial for effective communication in science.

One popular system is the Stock system naming, which is precise and informative as it represents the oxidation state of the metal ions in Roman numerals. For instance, in \(\mathrm{CuSO}_{4}\), knowing copper's oxidation state of +2 leads to the name Copper (II) sulfate.

In practicing chemical nomenclature, follow these steps:

• Identify the names of constituent ions: the metal and the polyatomic ion.
• Determine the oxidation state for the transition metal involved.
• Apply the Stock system name by adding the calculated oxidation number in parentheses.

Mastering chemical nomenclature allows chemists to accurately describe complex compounds and facilitate global scientific discourse.