Question

Name these compounds: (a) \(\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2} ;\) (b) \(\mathrm{HNO}_{2}\); (c) \(\operatorname{Cr} \mathrm{O}_{2} ;\) (d) \(\mathrm{KIO}_{3} ;\) (e) \(\mathrm{LiCN} ;\) (f) \(\mathrm{KIO} ;\) (g) \(\mathrm{Fe}(\mathrm{OH})_{2}\) (h) \(\mathrm{Ca}\left(\mathrm{H}_{2} \mathrm{PO}_{4}\right)_{2} ;\) (i) \(\mathrm{H}_{3} \mathrm{PO}_{4} ;\) (j) \(\mathrm{NaHSO}_{4} ;\) (k) \(\mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\); (l) \(\mathrm{NH}_{4} \mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2} ;(\mathrm{m}) \mathrm{MgC}_{2} \mathrm{O}_{4} ;\) (n) \(\mathrm{Na}_{2} \mathrm{C}_{2} \mathrm{O}_{4}\)

Short answer

(a) Barium nitrate; (b) Nitrous acid; (c) Chromium(IV) oxide; (d) Potassium iodate; (e) Lithium cyanide; (f) Potassium hypoiodite; (g) Iron(II) hydroxide; (h) Calcium dihydrogen phosphate; (i) Phosphoric acid; (j) Sodium hydrogen sulfate; (k) Sodium dichromate; (l) Ammonium acetate; (m) Magnesium oxalate; (n) Sodium oxalate

Step-by-step solution

Naming monoatomic ions

The first step is to know, how to name monoatomic ions. For metals in groups 1 and 2, and for metals that form cations with a single charge, the name of the metal is followed by 'ion'. For metals that form cations with more than one charge, the charge is indicated by a Roman numeral in parentheses after the name of the metal. For nonmetals, the end of the name of the element is dropped and replaced with 'ide', followed by the word 'ion'.

Naming polyatomic ions

Polyatomic ions are composed of more than one atom. Most of them are anions, and their names end in 'ite' or 'ate'. The 'ite' ending indicates a lower oxidation number, while 'ate' indicates a higher one. The number of oxygen atoms can also influence the name: one fewer oxygen atom than the 'ite' form is indicated by the prefix 'hypo-', while one more is indicated by the prefix 'per-'.

Naming the given compounds

Now, let’s name given compounds using these rules: (a) \(\mathrm{Ba(NO_{3})_{2}}\) is Barium nitrate. (b) \(\mathrm{HNO_{2}}\) is Nitrous acid. (c) \(\mathrm{CrO_{2}}\) is Chromium(IV) oxide. (d) \(\mathrm{KIO_{3}}\) is Potassium iodate. (e) \(\mathrm{LiCN}\) is Lithium cyanide. (f) \(\mathrm{KIO}\) is Potassium hypoiodite. (g) \(\mathrm{Fe(OH)_{2}}\) is Iron(II) hydroxide. (h) \(\mathrm{Ca(H_{2}PO_{4})_{2}}\) is Calcium dihydrogen phosphate. (i) \(\mathrm{H_{3}PO_{4}}\) is Phosphoric acid. (j) \(\mathrm{NaHSO_{4}}\) is Sodium hydrogen sulfate. (k) \(\mathrm{Na_{2}Cr_{2}O_{7}}\) is Sodium dichromate. (l) \(\mathrm{NH_{4}C_{2}H_{3}O_{2}}\) is Ammonium acetate. (m) \(\mathrm{MgC_{2}O_{4}}\) is Magnesium oxalate. (n) \(\mathrm{Na_{2}C_{2}O_{4}\) is Sodium oxalate.

Key concepts

Inorganic Chemistry

Inorganic chemistry is a branch of chemistry that focuses on compounds that are not based on carbon-hydrogen bonds, which distinguishes it from organic chemistry. This field encompasses a wide variety of substances including metals, minerals, and organometallic compounds. A key aspect of inorganic chemistry is understanding how different atoms combine and interact to form compounds. In the case of the compounds listed in the exercise, understanding the composition and reactions of inorganic substances helps in predicting their behavior and applications in various areas such as catalysis, materials science, and environmental engineering.

• Includes study of metals, minerals, and metal compounds.
• Covers a vast array of compounds not studied in organic chemistry.
• Crucial for applications in areas like catalysis and materials science.

Ions

Ions are atoms or molecules that carry an electrical charge due to the loss or gain of one or more electrons. Cations are positively charged ions, such as sodium (Na⁺), while anions carry a negative charge, like chloride (Cl^-). Understanding ions is crucial because they play a significant role in forming ionic compounds, which consist of metals and nonmetals bonded together by electrostatic forces. When naming ions:

• Cations formed by metals can have a single charge or multiple charges. For example, Iron can form Fe²⁺ (ferrous ion) or Fe³⁺ (ferric ion).
• Anions are usually named by taking the root of the element and adding "-ide" at the end, as in chloride or oxide.

Recognizing these naming conventions is crucial for understanding chemical formulas and the nature of different substances.

Polyatomic Ions

Polyatomic ions are ions that consist of more than one atom. They are typically stable groups of atoms that function as a single ion in chemical reactions. Common examples include sulfate (SO₄^2-) and nitrate (NO₃^-). It's essential to memorize both the composition and charge of these ions for accurate naming and formula writing. Here are some rules for naming polyatomic ions:

• The suffix '-ate' is used for ions with a higher number of oxygen atoms, while '-ite' is for fewer oxygen atoms, like sulfate vs. sulfite (SO₃^2-).
• Prefixes such as "per-" and "hypo-" also indicate variations in oxygen content, with "per-" indicating more and "hypo-" indicating fewer oxygen atoms.

These ions often appear in both simple and complex chemical compositions, making their study vital in inorganic chemistry.

Chemical Nomenclature

Chemical nomenclature is the systematic method of naming chemical compounds. It allows scientists and students to identify and communicate about substances accurately. There are different rules for naming compounds based on their types, such as ionic or covalent. For the compounds in the exercise, ionic compounds are named by first stating the cation followed by the anion.

• When naming ionic compounds, the metal (cation) is named first, followed by the nonmetal (anion) which often has an "-ide" suffix, like sodium chloride.
• For transition metals capable of forming ions with different charges, Roman numerals indicate the charge, such as Iron(II) chloride for FeCl₂.
• Covalent compounds use prefixes to indicate the number of each type of atom, like carbon dioxide or sulfur hexafluoride.

This systematic approach greatly aids in understanding and predicting the structure, properties, and behavior of compounds.