Question

Write the name of each compound: (a) \(\mathrm{ZnSO}_{4}\) (f) \(\mathrm{CoF}_{2}\) (b) \(\mathrm{Hg}_{2} \mathrm{~S}\) (g) \(\mathrm{Cr}\left(\mathrm{ClO}_{3}\right)_{3}\) (c) \(\mathrm{CuCO}_{3}\) (h) \(\mathrm{Ag}_{3} \mathrm{PO}_{4}\) (d) \(\mathrm{Cd}\left(\mathrm{NO}_{3}\right)_{2}\) (i) \(\mathrm{MnS}\) (e) \(\mathrm{Al}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{3}\) (j) \(\mathrm{BaCrO}_{4}\)

Short answer

(a) Zinc Sulfate, (f) Cobalt(II) Fluoride, (b) Mercury(I) Sulfide, (g) Chromium(III) Chlorate, (c) Copper(II) Carbonate, (h) Silver Phosphate, (d) Cadmium Nitrate, (i) Manganese(II) Sulfide, (e) Aluminum Acetate, (j) Barium Chromate

Step-by-step solution

- Naming Ionic Compounds with Simple Ions

To name simple ionic compounds, first name the cation (metal) and then the anion (non-metal or polyatomic ion), changing the end of the anion to 'ide' if it's a single element. For transition metals with variable charges, use Roman numerals in parentheses to indicate the charge of the cation.

- Naming Ionic Compounds with Polyatomic Ions

When the compound includes polyatomic ions, name the cation first followed by the name of the polyatomic ion without altering the ending.

- Apply Naming Rules to Given Compounds

Use the rules from Steps 1 and 2 to name each given compound: (a) ZnSO4 is Zinc Sulfate, (f) CoF2 is Cobalt(II) Fluoride, (b) Hg2S is Mercury(I) Sulfide, (g) Cr(ClO3)3 is Chromium(III) Chlorate, (c) CuCO3 is Copper(II) Carbonate, (h) Ag3PO4 is Silver Phosphate, (d) Cd(NO3)2 is Cadmium Nitrate, (i) MnS is Manganese(II) Sulfide, (e) Al(C2H3O2)3 is Aluminum Acetate, (j) BaCrO4 is Barium Chromate.

Key concepts

Cation and Anion Naming

Understanding how to name cations (positively charged ions) and anions (negatively charged ions) is fundamental when learning chemistry nomenclature. A cation, often a metal, retains the same name as the element. For instance, the cation in sodium chloride is simply called 'sodium.' Anions, typically non-metals or polyatomic ions, undergo a slight transformation where their suffix is changed to 'ide' when they are single elements. For instance, when chlorine becomes an anion, it is called 'chloride'.

In compounds with a simple anion like sulfide or oxide, the 'ide' ending suggests that the anion consists of a single element. This is a straightforward approach applied in many inorganic ionic compounds, helping students quickly identify components of a compound.

Transition Metals with Variable Charges

When it comes to transition metals, naming gets slightly more intricate due to their ability to adopt multiple charges. Unlike Group 1 and 2 metals which have fixed charges, transition metals can have variable oxidation states. That's why we use Roman numerals in parentheses to indicate the cation's charge. For example, iron can exist in the form of Fe²⁺ or Fe³⁺, named as iron(II) or iron(III), respectively.

In exercise solutions (f) 'CoF2' and (g) 'Cr(ClO3)3', knowing the charge is vital because cobalt can be Co²⁺ or Co³⁺, and similarly, chromium can exhibit multiple charges. Recognizing the correct charge is imperative for the correct nomenclature and ultimately for understanding the compound's behavior in chemical reactions.

Polyatomic Ions

Polyatomic ions are charged entities composed of two or more atoms covalently bonded, or of a metal complex that can act as a single unit in the context of acid-base chemistry or in the formation of salts. They always keep their unique names when forming compounds. Some common ones include SO₄^2- (sulfate), NO₃ (nitrate), and C₂H₃O₂^- (acetate).

As demonstrated in the exercises, when naming an ionic compound with a polyatomic ion, like aluminum acetate 'Al(C₂H₃O₂)₃', the ion’s name is not altered – acetate remains acetate. Correctly identifying and naming polyatomic ions is crucial since they often participate in chemical reactions where their entire structure acts as one unit.

Chemical Nomenclature Rules

The rules of chemical nomenclature are standardized systematic methods for naming chemical compounds. A robust understanding of these rules is essential to communicate the structural information of a compound effectively. The key is to start naming with the cation followed by the anion. If the anion is a single element, the suffix 'ide' is used. When dealing with compounds including polyatomic ions or transition metals, the specific rules for those cases apply.

Following steps for the systematic naming of the given compounds ensures clarity and precision in communication. For instance, Hg₂ S is described as Mercury(I) Sulfide rather than just mercury sulfide, which would fail to communicate the oxidation state of mercury in the compound. These rules are designed to avoid ambiguity and allow chemists to deduce the constituents and structure of compounds based solely on their names.