IPSUnit 11

Nomenclature Section 2

Binary Covalent Compounds

• Covalent compounds are those formed between elements that are both nonmetals both elements are to the right of

the staircase

• Use prefixes to tell how many atoms there are of each element because it is a covalent bond

(sharing electrons), there are no charges to work with

Binary Covalent Compounds

• The least electronegative one is listed first the element further to the left is listed first

• First element uses the name of the element

• Second element uses the name with the end changed to –ide

• Do NOT use mono- on the first element

Binary Covalent Compounds Practice

CCl4 Monocarbon Tetrachloride

Carbon Tetrachloride

N2O3Dinitrogen Trioxide

Binary Covalent Compounds Practice

S3Br5Trisulfur Pentbromide

Carbon Dioxide CO2

NO

Cl2O7

Bromine Pentafluoride

Trinitrogen Octasulfide

Binary Covalent Compounds Practice

Nitrogen Monoxide

Dichloride Hexaoxide

BrF5

N3S8

Compounds with Added Water

• Some ionic compounds have water molecules as part of their structure. These compounds are called hydrates.

• A hydrate is a compound that has water chemically attached to its ions and written into its chemical formula. The water is like a body guard; it is attached to the

molecule and stays with it

• A compound is said to be hydrated if it contains water.

Compounds with Added Water

• When writing a formula that contains a hydrate, the number of water molecules is shown after a dot (∙). Following the dot a number indicates how many water molecules are attached.

• The same prefixes are used when naming hydrates. • The main ionic compound is named the regular way,

but the number of water molecules in the hydrate is indicated by the prefix.

• The above substance is called Calcium Sulfate Dihydrate.

Compounds with Added Water

• When a solution of cobalt(II) chloride evaporates, pink crystals that contain six water molecules for each unit of cobalt chloride are formed. What is the formula?

CoCl2 • 6 H2O

Compounds without Added Water

• The water from a hydrate can be removed. When this happens it is now considered anhydrous.

• An anhydrous is a compound without water.