Naming and Formula Writing of Ionic Compounds Chapter 6

Ion Types Anion Cation Negative ion Formed when an atom gains electrons. Suffix changes to –ide when formed. Cation Positive ion Formed when an atom loses electrons. An atom cannot gain protons! Suffix does not change when formed.

Example Problem Tell whether each ion is a cation or anion or neither. Then tell the number of electrons gained or lost. Lastly name the ion. Na+ Fe3+ P3- F- Cation 1 e- lost Sodium Ion Cation 3 e- lost Iron Ion Anion 3 e- gained Phosphide Ion Anion 1 e- gained Fluoride Ion

Compound Conundrum CO2 NaHCO3 CH3OH NiNO3 C12H22O11 NaCl C3H7OH KI CaCO3 H2O

Types of Compounds Ionic compounds Made of a metal and a nonmetal. Very strongly bonded High melting point Crystalline solid White Smallest particle called a formula unit

Types of Compounds Molecular compounds Made of two or more nonmetals Weaker bonding Lower melting points Generally liquids and gases Colorless Smallest particle called a molecule

Compound Induction Lesson Find the one that are ionic, put and I by them. Find the ones that are molecular, put an M by them.

How to write names of ionic compounds Think of ionic compounds as having a first name and a last name Example 1 Sodium Chloride Example 2 Ammonium Sulfide Example 3 Potassium Nitrate

Compound Induction Lesson Name the ionic compounds on the induction sheet. Silver dihydrogen phosphate Potassium chromate Lithium chloride Antimony fluoride Magnesium nitrite Zinc phosphite

2nd Column Gold carbonate Iron nitride Mercury bromate Lead dichromate Tin bioxalate Strontium chlorate

3rd Column Aluminum thocyanate Barium hydorixde Nickel iodate Ammonium acetate Sodium hypochlorite

How to write formulas of ionic compounds. The first thing you must do is find the charges (oxidation numbers) of the elements or polyatomic ions in the formula. Example i 1 Example ii 2 Example iii 3

Group A Elements – look on the periodic table! Elements in group IA have a +1 charge. Elements in group IIA have a +2 charge. Elements in group IIIA have a +3 charge. Elements in group IVA have a +4 or -4 charge (we won’t be using these) Elements in group VA have a -3 charge. Elements in group VIA have a -2 charge. Elements in group VIIA have a -1 charge. Elements in group VIIIA have a 0 charge.

Group B Elements the name will tell you or the charge will be given and the charge will always be positive. Examples Iron (III) Oxide, the Fe has a +3 charge Tin (IV) Oxide, the Sn has a +4 charge Sn2+ = +2 charge

Metal Charges to know! Ag = +1 Zn = +2 Cd = +2

Golden Rules The sum of the oxidation numbers (charges) in a compound must equal zero! Add subscripts (little numbers) to elements to increase the number of them.

Example 1 Put together K and Cl Find the charges. it takes one of each to total up to zero The formula is KCl

Example 2 Put together Fe3+ and O Find the charges. it takes 2 Fe and 3 O to total up to zero The formula is Fe2O3

Example 3 Put together Ca and S Find the charges. it takes one of each to total up to zero The formula is CaS

Example 4 Put together Al and S Find the charges. it takes 2 Al and 3 S to total up to zero The formula is Al2S3

Example 5 Put together Ba and C2H3O2 Find the charges. it takes 1 Ba and 2 C2H3O2 to total up to zero The formula is Ba(C2H3O2)2

Example 6 Put together Ca and OH Find the charges. it takes 1 Ca and 2 OH to total up to zero The formula is Ca(OH)2

Example 7 Put together Mg and SO4 Find the charges. it takes 1 Mg and 1 SO4 to total up to zero The formula is MgSO4

Example 1 Strontium Chloride Strontium = Sr = +2 Chloride = Chlorine = Cl = -1 it would take 1 Sr and 2 Cl to total up to zero The formula is SrCl2

Example 2 Strontium Chlorite Strontium = Sr = +2 Chlorite = ClO2 = -1 it would take 1 Sr and 2 ClO2 to total up to zero The formula is Sr(ClO2)2

Example 3 Iron (II) Bioxalate Iron = Fe = +2 Bioxalate = HC2O4 = -1 it would take 1 Fe and 2 HC2O4 to total up to zero The formula is Fe(HC2O4)2

Example 4 Aluminum Carbonate Aluminum = Al = +3 Carbonate = CO3 = -2 it would take 2 Al and 3 CO3 to total up to zero The formula is Al2(CO3)3