Ionic Compounds

Lewis Dot Diagrams Chemical Interactions Occur between the Valence Electrons Dots: represent valence electrons

When atoms combine to make molecules, they form chemical bonds. Valence electron interaction

Forming Chemical Bonds Octet Rule Atoms will form bonds by: –Sharing –Giving or –Taking electrons to complete their octet Higher energy farther away from nucleus

Atoms form ions to have stable electron configurations (similar to noble gases) hh

Ionic Bonds Ionic Bonds form when one atom (nonmetal) gains electrons and the other atom (metal) loses electrons in order to gain stability.

Ionic Bonds form between a metal (cation) and a nonmetal (anion).

To form an ion, lithium will most likely: 1.Gain 1 electron 2.Gain 2 electrons 3.Lose 1 electron 4.Lose 2 electrons

Forming Chemical Bonds Lithium –Better to lose 1 electron or to gain 7 electrons? X

Therefore, as an ion lithium will have what charge?

Ionic Bonds Atoms gain or lose its electrons + NaCl - salt

Chemical Interactions Occur between the Valence Electrons Lewis structures are simpler to do & see

Formation of MgCl 2

Formation of Na 2 S

Write down the chemical formula for Aluminum Flouride

Formation of AlF 3

Today is a practice Day! We need to be able to name ions given chemical formula We need to be able to determine the chemical formula given the name

Valence Electrons  Noble Gas Structure = Octet 1,2 3,4,5,6,7,8

IONIC BONDS / Cations and Anions Cation – positive ions Transition Metals use Roman Numerals to tell you the ox # Anion – negative ions

Oxidation Numbers - indicated # of e’ lost, gained or shared. Ex. Oxidation number of chlorine is -1

Halogens will have an oxidation number of:

Alkaline earth metals will have an oxidation number of:

We will name binary compounds together Using pages Describe how to name cations and anions when they are by themselves

Naming Binary Ionic Compounds Write the name of the ionic compound, Ca 2 N 3. Write the name of the ionic compound, K 2 O.

What is the name of BeBr 2 ? 1.Boron bromine 2.Beryllium bromine 3.Bromide beryllide 4.Beryllium bromide 5.Beryllide bromide

Metals with Variable Charges Many transition metals can form more than one type of cation. For this reason, you must show the oxidation number in the name using Roman Numerals

Naming Binary Ionic Compounds with Transition Metal Cations Write the name of the ionic compound, Cu 2 O.. Write the name of the ionic compound, NiS.

What is the name for SnBr 2 ? 1.Bromide Tin 2.Tin Bromide 3.Tin (I) Bromide 4.Tin (II) Bromide 5.Tin (III) Bromide 6.Tin (IV) Bromide

What is the name for FeI 3 ? 1.Iron iodide 2.Iron (I) iodide 3.Iron (II) iodide 4.Iron (III) iodide

What is the name for MnS? 1.Manganese sulfide 2.Manganese (I) sulfide 3.Manganese (II) sulfide 4.Manganese (III) sulfide

Exceptions: Some of the transition metals have only one ionic charge: –Do not need to use roman numerals for these: –Silver is always 1+ (Ag 1+ ) –Cadmium and Zinc are always 2+ (Cd 2+ and Zn 2+ )

Writing Formulas for Binary Ionic Compounds Write the formula for barium iodide. Write the formula for sodium oxide. Write the formula for aluminum nitride. Write the formula for copper (I) sulfide.

Criss-Cross Method for Writing Formulas - You can write the oxidation number and criss-cross them as subscripts. - Note – if not in lowest terms you must reduce the subscripts (ex. Magnesium oxide) Al 3+ S = Al 2 S 3

What is the formula for aluminum bromide? 1.AlBr 2.AlBr 2 3.Al 3 Br 4.Br 3 Al 5.AlBr 3

What is the formula for magnesium oxide? 1.MgO 2.Mg 2 O 2 3.MgO 2 4.Mg 2 O 5.OMg

Write the formula for titanium (II) chloride. 1.TiCl 2.Ti 2 Cl 3.TiCl 2 4.Ti 2 Cl 2

Write the formula for tin (IV) oxide. 1.SnO 2.SnO 4 3.SnO 2 4.Sn 4 O 5.Sn 2 O

POLYATOMIC IONS Not all compounds are made of only 2 types of atoms poly – “many” Memorize the polyatomic ions from p. 170.

Tricks for Polyatomic Naming Perchlorateper+root+ate ClO 4 -1 chlorateroot+ateClO 3 -1 chloriteroot+iteClO 2 -1 Hypochloritehypo+root+iteClO -1 Prefixes and suffixes designate number of oxygens

Naming Polyatomic Ionic Compounds Polyatomic ionic compounds are named just like binary ionic compounds. Exception: be sure to enclose the polyatomic ion in parentheses before writing the subscript (only necessary if subscript is not 1). Ex. Barium hydroxide = Ba(OH) 2

Write the formula for Calcium Nitrate. 1.CaNO 2 2.Ca(NO 2 ) 2 3.Ca 2 NO 3 4.Ca 2 NO 2 5.Ca(NO 3 ) 2

Write the formula for Magnesium Phosphate. 1.MgPO 4 2.Mg 3 (PO 4 ) 2 3.Mg 4 (PO 3 ) 2 4.MgPO 3 5.Mg(PO 4 ) 2

Naming Ionic Compounds