Question

Name each of the following compounds. Assume the acids are dissolved in water. a. \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\) b. \(\mathrm{NH}_{4} \mathrm{NO}_{2}\) c. \(\mathrm{Co}_{2} \mathrm{~S}_{3}\) d. ICl e. \(\mathrm{Pb}_{3}\left(\mathrm{PO}_{4}\right)_{2}\) f. \(\mathrm{KClO}_{3}\) g. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) h. \(\mathrm{Sr}_{3} \mathrm{~N}_{2}\) i. \(\mathrm{Al}_{2}\left(\mathrm{SO}_{3}\right)_{3}\) j. \(\mathrm{SnO}_{2}\) k. \(\mathrm{Na}_{2} \mathrm{CrO}_{4}\) I. HCIO

Short answer

a. Acetic Acid b. Ammonium Nitrite c. Cobalt(III) Sulfide d. Iodine Monochloride e. Lead(II) Phosphate f. Potassium Chlorate g. Sulfuric Acid h. Strontium Nitride i. Aluminum Sulfite j. Tin(IV) Oxide k. Sodium Chromate l. Hypochlorous Acid

Step-by-step solution

Naming HC2H3O2

This compound is an acid dissolved in water. Its formula is HC2H3O2, and it is called Acetic Acid. b.

Naming NH4NO2

This is an ionic compound because it is formed by the ammonium (NH4⁺) cation and the nitrite (NO2⁻) anion. It is called Ammonium Nitrite. c.

Naming Co2S3

This is an ionic compound formed by the cobalt (Co) cation and the sulfide (S) anion. The compound's name is Cobalt(III) Sulfide, indicating the cation's oxidation state by the Roman numeral. d.

Naming ICl

This is a covalent compound formed by the two nonmetals iodine (I) and chlorine (Cl). It is called Iodine Monochloride. e.

Naming Pb3(PO4)2

This is an ionic compound formed by the lead (Pb) cation and the phosphate (PO4) anion. The compound's name is Lead(II) Phosphate, indicating the cation's oxidation state by the Roman numeral. f.

Naming KClO3

This is an ionic compound formed by the potassium (K) cation and the chlorate (ClO3) anion. It is called Potassium Chlorate. g.

Naming H2SO4

This compound is an acid dissolved in water. Its formula is H2SO4, and it is called Sulfuric Acid. h.

Naming Sr3N2

This is an ionic compound formed by the strontium (Sr) cation and the nitride (N) anion. The compound's name is Strontium Nitride. i.

Naming Al2(SO3)3

This is an ionic compound formed by the aluminum (Al) cation and the sulfite (SO3) anion. The compound's name is Aluminum Sulfite. j.

Naming SnO2

This is an ionic compound formed by the tin (Sn) cation and the oxide (O) anion. The compound's name is Tin(IV) Oxide, indicating the cation's oxidation state by the Roman numeral. k.

Naming Na2CrO4

This is an ionic compound formed by the sodium (Na) cation and the chromate (CrO4) anion. It is called Sodium Chromate. l.

Naming HCIO

This compound is an acid dissolved in water. Its formula is HCIO, and it is called Hypochlorous Acid.

Key concepts

Acids and Bases

Understanding the difference between acids and bases, as well as how to name them, is fundamental in chemistry.

Acids are substances that can donate a proton (H+) in a reaction, and they typically taste sour. When dissolved in water, they increase the concentration of hydrogen ions (H+). A simple example is acetic acid (HC2H3O2), which gives vinegars their characteristic tang. In naming acids, we look at the anion they form when dissolved. For acids with anions ending in '-ide' like hydrochloric acid (HCl), we add the prefix 'hydro-' and change the ending to '-ic' followed by the word 'acid'. For those with anions ending in '-ate' or '-ite', such as sulfuric acid (H2SO4) from the sulfate ion (SO4) or chlorous acid from the chlorite ion (ClO2), the endings '-ate' and '-ite' are replaced with '-ic' and '-ous', respectively, also followed by 'acid'.

In contrast, bases are substances that can accept a proton or donate a hydroxide ion (OH-) in a reaction. They are usually bitter and slippery to touch, like sodium hydroxide (NaOH). Naming bases is generally simpler, as we use the metal's name, such as 'sodium', followed by 'hydroxide'.

Ionic Compounds

Ionic compounds are formed when metals transfer electrons to nonmetals, resulting in a solid with a characteristic high melting point and the ability to conduct electricity when melted or dissolved in water. They are composed of positively charged ions (cations) and negatively charged ions (anions).

The naming of ionic compounds requires identifying the cation and the anion. For monatomic cations (single atoms with a positive charge), we simply use the element's name, like sodium in sodium chloride (NaCl). Anions, generally, get the suffix '-ide', such as chloride in NaCl. However, for polyatomic ions (groups of atoms with a charge), we use the name of the entire ion, like sulfate in lead(II) sulfate (PbSO4). If the cation can have different charges, like iron, we specify the charge with Roman numerals in parentheses, like in iron(III) oxide (Fe2O3).

Chemical Nomenclature

Chemical nomenclature is the systematic naming of chemical compounds and is essential for clear communication in the scientific community. Let's consolidate some important points concerning naming:

• If the compound is molecular (nonmetals bonding, like CO2), use prefixes like 'mono-', 'di-', 'tri-', to denote the number of atoms. For ionic compounds (metal and nonmetal, like NaCl), we don't use such prefixes.
• We must also consider the oxidation state for metals that can have more than one. The oxidation state is indicated by a Roman numeral in parentheses right after the metal's name. For example, in 'manganese(IV) oxide', the (IV) indicates the +4 oxidation state of manganese (Mn).
• For acids, the nomenclature changes depending on whether they are binary acids (like hydrochloric acid, HCl), or ternary (like sulfuric acid, H2SO4), reflected by using the prefixes 'hydro-' and suffixes '-ic' or '-ous' as described earlier.

By adhering to these rules, students and chemists can accurately describe and understand the composition of different chemical compounds.