Naming Binary Covalent

Compounds

Covalent Compounds

Formed between two non-metals

Valence electrons are shared between atoms

Binary Covalent Compounds

Contain just two different types of non-metal elements

Some Different Rules

Covalent compound have a few rules to naming to those of ionic compound

When non-metals combine they can form several different covalent compounds

Example: Carbon and oxygen combine to form two common covalent compounds CO2 and CO

Each of these compounds have their own names

Rules for Naming Covalent Compounds

1. Always write/name the element with more metallic character first. Metallic character increases going from right to left, and top to bottom on the Periodic Table.

Rules for Naming Covalent Compounds

2. Then write/name the second (less metallic) element, changing the ending of its name to –”ide”

Rules for Naming Covalent Compounds

3. Since nonmetals often combine in different proportions to form a number of different compounds, prefixes must be included in the names to indicate the numbers of each kind of atom present.

Prefixes

Number Prefix Number Prefix

1 mono- 6 hexa-

2 di- 7 hepta-

3 tri- 8 octa-

4 tetra- 9 nona-

5 penta- 10 deca-

Example

P4S3

Tetraphosphorus trisulfide

Prefix Exception

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

Example:

BCl3 boron trichloride

Prefix Exception

Never use any prefixes at all for simple covalent compounds containing Hydrogen

Example:

HF hydrogen fluoride

Prefix Exception

The "o" and "a" endings of these prefixes are dropped when they are attached to "oxide."

Example:

N2O5 dinitrogen pentoxide

Order Exceptions

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

Examples:

NH3 ammonia CH4 methane H2O water

Diatomic Molecules

Element that consists of two atoms combined

Examples:

F2 fluorine

N2 nitrogen

Practice Naming Covalent Compounds

SiF4

silicon tetrafluoride

Practice Naming Covalent Compounds

N2S3

dinitrogen trisulfide

Practice Naming Covalent Compounds

HBr

hydrogen bromide

Practice Naming Covalent Compounds

Br2

bromine

Practice Naming Covalent Compounds

N10O4

decanitrogen tetroxide

Practice Writing Formulas of Covalent Compounds

B2H6

diboron hexahydride

Practice Writing Formulas of Covalent Compounds

NBr3

nitrogen tribromide

Practice Writing Formulas of Covalent Compounds

SCl6

Sulfur hexachloride

Practice Writing Formulas of Covalent Compounds

P2O5

diphosphorus pentoxide

Practice Writing Formulas of Covalent Compounds

N3S

trinitrogen monosulfide

Practice Writing Formulas of Covalent Compounds

P8O7

octaphosphorus heptoxide

Review Worksheet

Naming Covalent Compounds

Write the Chemical Formula for the following Covalent Compound

SbBr3

Antimony tribromide

Write the Chemical Formula for the following Covalent Compound

B6Si

Hexaboron silicide

Write the Chemical Formula for the following Covalent Compound

ClO2

Chlorine dioxide

Write the Chemical Formula for the following Covalent Compound

HI

Hydrogen iodide

Write the Chemical Formula for the following Covalent Compound

IF5

Iodine pentafluoride

Write the Chemical Formula for the following Covalent Compound

N2O3

Dinitrogen trioxide

Write the Chemical Formula for the following Covalent Compound

NH3

ammonia

Write the Chemical Formula for the following Covalent Compound

PI3

Phosphorus triiodide

Write the Names for the following Covalent Compound

P4S5

Tetraphosphorus pentasulfide

Write the Names for the following Covalent Compound

O2

oxygen

Write the Names for the following Covalent Compound

SeF6

Selenium hexafluoride

Write the Names for the following Covalent Compound

Si2Br6

Disilicon hexabromide

Write the Names for the following Covalent Compound

SCl4

Sulfur tetrachloride

Write the Names for the following Covalent Compound

CH4

methane

Write the Names for the following Covalent Compound

B2Si

Diboron silicide

Write the Names for the following Covalent Compound

NF3

Nitrogen trifluoride