Naming Rules

Question 1

Three main types of chemical formulas:

Answer 1

Organic, Molecular Inorganic (covalent), and Ionic

Question 2

Organic Compounds

Answer 2

contains predominantly carbon and hydrogen atoms

Question 3

Molecular Inorganic/

Simple Covalent Compounds

(Non-metals with non-metals)

Answer 3

it contains only nonmetal atoms and inorganic (not predominantly carbon and hydrogen atoms)

Question 4

Organic Formulas

Answer 4

follow the convention of placing C first in the formula, followed by H, followed by the remaining symbols in alphabetical order

Question 5

Molecular Inorganic Formulas

Answer 5

generally follow the convention of placing elements of groups 13 to 15 first (in that order), followed by the rest of the symbols starting with those furthest to the left in the periodic table. Elements in the same column are listed alphabetically

Question 6

Ionic Compounds Formula

Answer 6

Ionic compounds are always made up of a cation (positive ion) and an anion (negative ion). Metal + nonmetal.

The cation is always listed first in the formula.

1. Name the cation (See rules for cation names)
2. Name the anion with the suffix -ide

Ex: NaCl sodium chloride, (NH4)2SO4 ammonium sulfate, NaHCO3 sodium bicarbonate

Question 7

Three Rules for naming Cations:

Answer 7

1. Monatomic positive ions have the name of the element from which they are formed.
2. Some metals form positive ions in more than one oxidation state.
   
   1. suffixes -ous and -ic (Fe²⁺ ferrous, Fe³⁺ferric, Sn²⁺stannous, Sn⁴⁺stannic….)
   2. We use Roman numeral in parentheses immediately after the name of the element. Fe²⁺ iron(II), Fe³⁺ iron (III), Sn²⁺ tin(II), Sn⁴⁺ tin(IV), Cu⁺ copper(I), Cu²⁺ copper(II)
3. Polyatomic positive ions often have common names ending with the suffix -onium. (H³O⁺ hydronium, NH⁴⁺ ammonium)

Question 8

Common Polyatomic Negative Ions (Anions)

Answer 8

-1 ions

HCO₃^-, bicarbonate, HSO₄^-, hydrogen sulfate (bisulfate)

CH₃CO₂^-, acetate, ClO₄^-, perchlorate

NO₃^-, nitrate, ClO₃^-, chlorate

NO₂^-, nitrite, ClO₂^-, chlorite

MnO₄^-, permanganate, ClO^-, hypochlorite

CN^-, cyanide, OH^-, hydroxide

-2 ions:

CO₃^2-, carbonate, O₂^2-, peroxide

SO₄^2-, sulfate, CrO₄^2-, chromate

SO₃^2-, sulfite, Cr₂O₇^2-, dichromate

S₂O₃^2-, thiosulfate, HPO₄^2-, hydrogen phosphate

-3 ions

PO₄^3-, phosphate, AsO₄^3-, arsenate

BO₃^3-, borate

Question 9

4 Anion Naming rules:

Answer 9

1. The -ite ending indicates a low oxidation state. Thus,the NO₂^- ion is the nitrite ion.
2. he -ate ending indicates a high oxidation state. The NO₃^- ion, for example, is the nitrate ion.
3. The prefix hypo- is used to indicate the very lowest oxidation state. The ClO- ion, for example, is the hypochlorite ion.
4. The prefix per- (as in hyper-) is used to indicate the very highest oxidation state. The ClO₄^- ion is therefore the perchlorate ion.

[Exceptions to these generalizations: hydroxide (OH^-), cyanide (CN^-), and peroxide (O₂^2-) ions have the -ide ending because they were once thought to be monatomic ions.

Question 10

Simple Covalent Compounds

(Non-metals with non-metals)

Answer 10

The name of the atom in the positive oxidation state is listed first. The suffix -ide is then added to the stem of the name of the atom in the negative oxidation state.

The number of atoms of an element are told by the prefixes:

1. mono- (
2. di-
3. tri-
4. tetra-
5. penta-
6. hexa-
7. hepta-
8. octa-
9. nona-
10. deca-

These are also used for hydrates.

Question 11

Flowchart for nomenclature: