Chemistry Nomenclature RC#1

Simple names are used for ionic compounds (and some covalent compounds) where only one compound is made from those elements.

Latin names are used for ionic compounds (and some covalent compounds) where more than one compound is made from those elements.

Stock names are used for ionic compounds and covalent compounds where more than one compound is made from those elements. (Actually, Stock names can also be used for ionic compounds and covalent compounds where only one compound is made from those elements, but the Stock names are the same as simple names in those cases.)

Prefix names are used for covalent compounds. (There are a few cases where prefix names can be used for ionic compounds, but you have to know the specific cases where that is permissible if you want to do that.)

A monatomic ion is ion consisting of a single atom.

Example: Calcium carbonate consists of the monatomic ion Ca2⁺ and the polyatomic ion CO₃²⁻.

If an ion contains more than one atom, even if these atoms are of the same element, it is called a polyatomic ion.

Example: Calcium carbonate consists of the monatomic ion Ca2⁺ and the polyatomic ion CO₃²⁻.

A positively charged ion, i.e., one that would be attracted to the cathode in electrolysis. (More protons than electrons.)

A type I binary ionic compound which contains a metal (cation) forms only one type of ion.

A type II ionic compound contains a metal that forms more than one type of ion, i.e., ions with different charges.

The monatommic ions listed are type I binary compounds, which means that they would be attracted to the cathode in electrolysis.

An anion is a negatively charged ion, i.e., one that would be attracted to the anode in electrolysis. (More electrons than protons.)

These monatomic ions listed are cations in type II binary compounds , which contains metals that form more than one type of ion, i.e., with different charges.

Positive ion followed be negative ion.
Examples: NaCl for Sodium Chloride and NaHCO₃ is Sodium Bicarbonate

They have the name of the element from which they were formed. Examples: Na⁺ is sodium, Zn²⁺ is Zinc, K⁺ is Potassium, and H⁺ is hydrogen

They indicate when a metal can form positive ions in more than one oxidation state.
Example: Fe2⁺ is Ferrous and Fe3⁺ is Ferric, Sn2⁺ is Stannous and Sn4⁺ is Stannic, and Cu⁺ is Cuprous and Cu2⁺ is Cupric

When the prefix bi- is added to a name, a hydrogen is added to the ion’s formula and its charge is increased by 1. This is a consequence of the hydrogen ions +1 charge.

Roman numerals indicate the charge on the ion.
Example: Fe² is iron(II) and Fe³ is iron(III), Sn²⁺ is tin(II) and Sn⁴ is tin(IV)

An alternate to the prefix bi- is to use the word hydrogen in its place: the anion derived from H⁺+ CO²₋₃, HCO⁻₃ can be clled hydrogen carbonate versus bicarbonate.

It indicates the change

A molecular ion, which is a charged chemical species, composed of two or more ions covalently bonded or of a metal complex that can be considered to be acting as a single unit.

-ate is the basic name of an ion. Example: Sulfate

The suffix -ite reduces the oxygen by one. Example:Sulfite

(The charge is not affected.)

The prefix per- adds an oxygen. Example: Persulfate

(The charge is not affected.)

Keeping the suffix -ite and adding the prefix -hypo reduces the number of oxygens by one or more.

Example: Hyposulfite

(The charge is not affected.)

The name of the ion usually ends in either -ite or -ate. The -ite ending indicates a low oxidation state. Thus,the NO₂⁻ ion is the nitrite ion.

The -ate ending indicates a high oxidation state. The NO3- ion, for example, is the nitrate ion.

The prefix hypo- is used to indicate the very lowest oxidation state. The ClO- ion, for example, is the hypochlorite ion.

The prefix per- (as in hyper-) is used to indicate the very highest oxidation state. The ClO4- ion is therefore the perchlorate ion.

There are only a handful of exceptions to these generalizations.

The names of the hydroxide (OH-), cyanide (CN-), and peroxide (O22-) ions, for example, have the -ide ending because they were once thought to be monatomic ions.

We use the suffix’s -ate and -ite and prefixes per- and hypo- to work with the most common elements such as sulfate, phosphate nitrate, and chlorate.

oxidation state −1 +1 +3 +5 +7

anion name chloride hypochlorite chlorite chlorate perchlorate

formula Cl− ClO− ClO⁻₂ ClO⁻₃ ClO⁻₄

These rules will not work with all polyatomic anions, but they do work with the most common ones (sulfate, phosphate, nitrate, chlorate).

CH₃COO− or C₂H₃O⁻₂
2

C₆H₅COO⁻ or C₇H₅5O⁻₂

NH⁺₄

H₂F⁺

Negative ions that have a single atom are named by adding the suffix -ie to the stem of the name of the element.

Examples:
F- fluoride O2- oxide
Cl- chloride S2- sulfide
Br- bromide N3- nitride
I- iodide P3- phosphide
H- hydride C4- carbide

Common Polyatomic Negative Ions
-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

Common Polyatomic Negative Ions

-2 ions

CO₃²⁻ carbonate
O₂²⁻ peroxide
SO₄²⁻ sulfate
CrO₄²⁻ chromate
SO₃²⁻ sulfite
Cr₂O₇²⁻ dichromate
S₂O₃²⁻ thiosulfate
HPO₄²⁻ hydrogen phosphate

Common Polyatomic Negative Ions

-3 ions

PO₄³⁻ phosphate
AsO₄³⁻ arsenate
BO₃³⁻ borate

…

…

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Naming Simple Covalent Compounds

( Non-metals with non-metals )

Oxidation states also play an important role in naming simple covalent compounds. 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.
HCl hydrogen chloride
NO nitrogen oxide
BrCl bromine chloride

As a rule, chemists write formulas in which the element in the positive oxidation state is written first, followed by the element(s) with negative oxidation numbers.

The number of atoms of an element in simple covalent compounds is indicated by adding one of the following Greek prefixes to the name of the element.
1 mono- 6 hexa-
2 di- 7 hepta-
3 tri- 8 octa-
4 tetra- 9 nona-
5 penta- 10 deca-

The prefix mono- is seldom used because it is redundant. The principal exception to this rule is carbon monoxide (CO).

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.

It produces a stable balance of attractive and repulsive forces between atoms when they share electrons. For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full outer shell, corresponding to a stable electronic configuration

Physical properties Covalent compounds

States (at room temperature) Solid, liquid, gas
Electrical conductivity Usually none
Boiling point and Melting point Varies, but usually lower than
ionic compounds
Solubility in water Varies, but usually lower than
ionic compounds
Thermal conductivity Usually low

Covalent bonds are affected by the electronegativity of the connected atoms. Two atoms with equal electronegativity will make nonpolar covalent bonds such as H-H. An unequal relationship creates a polar covalent bond such as with H−Cl.

There are three types of covalent substances: individual molecules, molecular structures, and macromolecular structures.

Individual molecules have strong bonds that hold the atoms together, but there are negligible forces of attraction between molecules. Such covalent substances are usually gases, for example, HCl, SO₂, CO₂, and CH₄.

In molecular structures, there are weak forces of attraction. Such covalent substances are low-boiling-temperature liquids (such as ethanol), and low-melting-temperature solids (such as iodine and solid CO₂).

Macromolecular structures have large numbers of atoms linked in chains or sheets (such as graphite), or in 3-dimensional structures (such as diamond and quartz). These substances have high melting and boiling points, are frequently brittle, and tend to have high electrical resistivity. Elements that have high electronegativity, and the ability to form three or four electron pair bonds, often form such large macromolecular structures.

Simple covalent compounds are generally named by sing prefixes to indicate how many atoms of each element are show in the formula. The ending of the element (the most negative one) is changed to -ide.

There is some overlap between covalent and ionic compounds, but many of these compounds have common names such as methane, ammonia, and water.

The mono- prefix is usually not used for the first element in the formula.

Generally, they are in the same left-to-right order that they are on the periodic table, except that you would have to squeeze hydrogen in between nitrogen and oxygen.

Answers:
phosphorus trihydride

dinitrogen trioxide

carbon monoxide

sulfur dioxide

hydrogen monoiodide (This compound also is often called by its simple name, hydrogen iodide, since there is only one combination of just hydrogen and iodide.)

sulfur hexachloride

CH₄
Because there is one carbon atom and four hydrogen atoms bonded together. However, another name for this compound is methane because it was named long before the formula was figured out.

NH₃ which demonstrates that it contains one nitrogen and three hydrogen atoms bonded together. This compound was also named long before it’s formula was figured out. It’s also called ammonia.

H₂O is commonly known as water.

HCl. However, note that in this case there are no prefixes because there is only one atom of the first element in the molecule, the prefix mono might or might not be used. Usually it is left off.

The prefix mono- is typically used when elements can combine to form more than one compound and one of those compounds has just one atom of that element.

Examples:
Formula Common Name Prefix Names
CH₄ methane carbon tetrahydride
NH₃ ammonia nitrogen trihydride
H₂O water dihydrogen monoxide
HCl hydrogen chloride

Silicon tetrahydride (Commonly known as silane.)

Phosphorous Trihydride (Commonly known as phosphine.)

H₂S

(Commonly known as sulfur-hydrogen because it is the most common, expected, and most reasonable fo teh sulfur-hydrogen compounds. The lack of prefixes in this name leaves it to you and your understanding of bonding and electron structure to figure out that there are two hydrogens and one sulfur.)

hydrogen bromide

The prefixes used are mono-, di-, tri-, tetra-, penta-, hexa-, and so forth. These are the first six prefixes: mono- is 1, di- is two, etc. The “o” and “a” endings of these prefixes commonly are dropped when they are attached to “oxide.”

We use Stock names when more than one compound can be formed with the same elements. That occurs when the metal is a transition metal that forms more than one ion.

Nonmetals often can combine to make more than one compound also – for example, carbon and oxygen can combine in a 1-to-1 ratio in CO or in a 1-to-2 ratio in CO2.

Since different nonmetals have different electronegativities (the ability to attract shared electrons), the atoms are not sharing their electrons equally; one of the atoms in a bond will have a stronger pull for those shared electrons.

Assign an oxidation number to each element. There are specific differences between oxidation numbers and ion charges , but for now you can simplify the concept by thinking about oxidation numbers as “psuedo charges.” When we figure out the correct ratios for the elements we will deal with the oxidation numbers as if they are actual charges (even though we know that is not completely correct).

Formula: CO

Oxidation states:
C²⁺ and O²⁻
(The Roman numeral tell us the oxidation number of the element directly in front of it, just like in ionic compounds.) The oxidation number of the other element is determined by its position on the periodic table.

Stock name: gold(I) nitride

Oxidation States: Au+ and N3- (Start with the N ion – it should be 3- based on its position on the periodic table. The Au must be 1+ since three Au+ ions are used to balance the one N3- ion.)

Stock name: carbon(IV) chloride

Oxidation States: C4+ and Cl- (Start with the Cl. Iit should have a 1- oxidation state based on its position on the periodic table. The C must be 4+ since one C is used to balance the four Cl atoms.)

Answers:

CO₂ is carbon(IV) oxide. (Oxide should be O²⁻ so with a ratio of 2 O to 1 C, the C should be C )

N₂O₄ is nitrogen(IV) oxide. (Oxide is O²⁻ again so the nitrogen must be N⁴⁺ since the ratio is 2 O to 4 N.)

carbon(IV) fluoride is CF₄. (The Roman numeral shows that we have C⁴⁺ and F is F¹⁻, so they must be combined in a 1-to-4 ratio.)

Stock name: Ions present:
iron(II) oxide Fe2+ and O2

HCl, HBr, HCN

These solutions are named by adding the prefix hydro- to eht ename of the compound and then replacing the suffix -ide with -ic.

Hydrogen chloride (HCl) dissovled in water forms hydrochloric acid.

The formula for hydrogen bromide is (HBr) and when combined with water it becomes hydrobromic acid.

Hydrogen cyanid (HCN) is combine with water to make hydrocyanic acid.

HCl hydrochloric acid
HF hydrofluoric acid
H2S hydrosulfuric acid

Answers to converting compounds to acids.

acetic acid CH₃CO₂H
carbonic acid H₂CO₃
boric acid H₃BO₃
nitric acid HNO₃
sulfuric acid H₂SO₄

HClO₂ chlorous acid
HNO₂ nitrous acid
H₂SO₃ sulfurous acid
HClO hypochlorous acid

NaHCO₃ sodium hydrogen carbonate (also known as sodium bicarbonate)

NaHSO₃ sodium hydrogen sulfite (also known as sodium bisulfite)

KH₂PO₄ potassium dihydrogen phosphate