(2.2) MOLECULAR COMPOUNDS (p130-131)

Naming and all that.

Molecular Compounds

Molecular compounds are formed by combining two non-metals.

They do so by “sharing” electrons. The bond formed by sharing

electrons is called a covalent bond.

Properties of Molecular Compounds

Often soft, liquid, solid or gas. If they dissolve in water, they form

solutions that do no conduct electricity.

Tend to have relatively low melting points.

Naming Molecular Compounds

Naming molecular compounds is different than naming ionic compounds because non-metals can combine in many different ways.

Naming Molecular Compounds

Eg. carbon and oxygen can combine 2 different ways!!!

carbon monoxide CO

carbon dioxide CO2

Naming Molecular Compounds

To name a molecular compound prefixes are used to show the number of each type of atom.

Prefix systemPrefix Number

mono 1

di 2

tri 3

tetra 4

penta 5

hexa 6

hepta 7

octa 8

nona 9

deca 10

Examplesname formula

sulfur trioxide

dihydrogen monosulfide

SiO2

CF4

N2O5

disulfur dinitride

Examplesname formula

sulfur trioxide SO3

dihydrogen monosulfide H2S

silicon dioxide SiO2

carbon tetrafluoride CF4

dinitrogen pentoxide N2O5

disulfur dinitride S2N2

NOTE: never have 2 vowels in a row between the prefix and element ex: 2 “o’s” monooxide

Naming Molecular Compounds

A molecular compound has a two-part name:

firstfirst secondsecond

Non-metal Non-metal

Uses prefix for number

Uses prefix for number

Keeps its name Changes ending to “ide”

Common Molecular Compounds

You must know these…. H2O water H2O2 hydrogen peroxide CH4 methane CO2 carbon dioxide

Practice

-Video to recap!-Do: Worksheet 2.2 (C) - NAMING

MOLECULAR COMPOUND PRACTICE-Quiz-Molecular Compounds next class

TEST UNIT 1-Part A on THURSDAY!

Classwork

Workbook- 46-48- 50-52 Worksheet 2.2 (D)-naming ALL!

REMINDER:TEST UNIT 1-Part A on THURSDAY, FEB 23