Topic 3.0 – Chemical Compounds

Chemical Compounds Element – simplest form of matter; cannot be broken down any further Ex. Au, carbon Compound – formed from two or more elements  Can be separated into its elements by using electricity  Ex. NaCl, H 2 0

Compounds There are 2 types of compounds: 1) Ionic compounds 2) Molecular Compounds Each compound can be represented by its name or chemical formula Chemical formula – symbols and numbers representing which atoms and how many are in the compound

Fill out the chart. Elements# of Atoms of each element Total # of atoms H20H20 NaCl MgCl 2 Fe 2 O 3

IUPAC – international union of pure and applied chemistry -creates rules for naming compounds has lost or gained electrons Ion- is an atom that has lost or gained electrons; it is a charged atom -ions are formed only when metals and non-metals are dissolved in water or in an ionic compound**

A. Ionic Compounds metal ion non-metal *A compound that is formed from a metal ion and a non-metal ion.* Properties of Ionic Compounds High melting point (are usually solids) Good conductivity when melted or dissolved in water Solids are crystal shape Break into ions when dissolved in water

A. Ionic Compounds Naming : 1. Name the metal ion first. 2. Name the non-metal second. 3. Write in all lowercase letters 4. Change the ending of the non-metal to –ide.

A. Ionic Compounds Ex. BaCl 2 Ex. K 2 S Ex. Sr 3 P 2

Ex. AlP Ex. ZrO 2 Ex. Li 2 S

A. Ionic Compounds Formulas: 1. Write down the metal and non-metal symbols and charges. 2. Balance the + and – charges by adding ions. 3. Write the metal symbols first. Write the number of metal atoms needed as a subscript. 4. Write the non-metal symbols second. Write the number of the non-metal atoms needed as a subscript.

Ionic Compounds Ex. barium sulphide Ex. potassium oxide Ex. Calcium nitride

Ionic Compounds Ex. Aluminum chloride Ex. Sodium oxide Ex. Silver chloride

Ionic Compounds Multivalent ions Multivalent ions are those metal atoms that have 2 or more charges listed Ex. Sn 2+ or 4 +, Pb 2 + or 4 + -when you name compounds with these, you MUST write down which charge is being used using roman numerals. I – one, II – two, III – three, IV- four, V-five VI - six

Ionic compounds FeCl3 Fe2O3 NiS

CuCl CuBr 2 PtO 2

Molecular Compounds A compound made from >2 non-metal atoms (no metals) Properties of Molecular Compounds Are solid, liquid or gas at room temp Do not conduct (are insulators) Low melting and boiling points Ex. Sugar, H20, CO2

Molecular Compounds Naming 1. Write down the prefix of the first atom (except – mono). 2. Write down this atoms name. 3. Write down the second atoms prefix (all). 4. Write down this atoms name. Change ending to –ide.

Molecular compounds Prefixes – must memorize 1- mono 2- di 3-tri 4- tetra 5 - penta

Molecular Compounds Ex. CO2 Ex. CO Ex. N2O

Molecular Compounds CCl4 SF5 N2O3

Molecular Compounds Writing the Formula 1. Write down the atom name and its prefix.

Molecular compounds Ex. sulphur dibromide Ex. silicon tetrafluoride Ex. phosphorus trichloride

Common Molecular Compounds These compounds are used so often they have common names: > ammonia NH3 > water H20 > glucose C6H12O6 > hydrogen peroxide H2O2 >

Ionic or Molecular? Ex. AlCl3 Ex. NaCl Ex. SO3

Matching Match the name to the unknown substance: sodium chloride or sulphur dioxide Melting PointConductivityStateIdentity #1 highHighSolid #2Low Gas