SNC 2D1 September 14 th, 2011

 Use Lewis dot diagrams to show the ionic bond created between sodium and chlorine.  What is its name?

 The number of electrons that are given up by the metal must equal the number of electrons that are gained by the non-metal  Example: aluminum chloride

Elements in Ionic CompoundName of Ionic Compound Magnesium and phosphorusMagnesium phosphide Sodium and chlorineSodicum chloride Calcium and bromineCalcium bromide Aluminum and oxygenAluminum oxide CompoundName MgBr 2 Magnesium bromide Al 2 O 3 Calcium iodide CaI 2 Aluminum oxide KClPotassium chloride

 Ionic compounds tend to be solid at room temperature and are organized in a large repeated pattern

 The formula represents the ratio of the ions that make up the crystal  Potassium Bromide  Magnesium Chloride  Aluminum Sulfide

StepsExample 1 Aluminum Fluoride Example 2 Magnesium Nitride 1. Identify each ion and its charge Aluminum: Al 3+ Fluoride: F - Magnesium: Mg 2+ Nitride:N Determine the total positive charge and the total negative charge needed to equal zero. Al 3+ : 1(3+) = 3+ F - : 3(-) = 3- (3+) + (3-) = 0 Mg 2+ : 3(2+) = 6+ N 3- : 2(3-) = 6- (6+) + (6-) = 0 3. Note the ratio of cations to anions 1Al 3+ : 3F - 3Mg 2+ :2 N Use subscripts to show the ratio of ions AlF 3 Mg 3 N 2

 Write the ions beside each other  Take the amount of charge (ignoring the sign) from the cation and make it the subscript for the anion in your formula  Take the amount of charge (again, ignoring the sign) from the anion and make this number the subscript for the cation in your formula  Example: Magnesium Chloride

 Some metals have more than one ion charge listed in the periodic table  These multivalent metals can form different ions depending on which chemical reaction they undergo  Some examples are copper and iron  *Most common is written first on periodic table*  *Use roman numerals to express different multivalent forms* (I, II, IV, etc.)

StepsExample: Cu 3 N 1. Identify the metalCopper (Cu) 2. Verify the metal can form more than one kind of ion by checking the periodic table Cu + and Cu Determine the ratio of the ions in the chemical formula 3 copper : 1 nitride 4. Note the charge of the anion3- 5. The positive and negative charges must balance out so that the net charge is zero. Total negative charge: 3- Total positive charge: Determine what charge the metal ion must have to balance the anion. 3(Cu ? )=3+ Therefore the charge on the copper must be Write the name of the metal ion.The name of the metal ion is copper (I). 8. Write the name of the compound.Copper(I) nitride

 SnS 2

 Determine what lead is in PbS 2.  Hint! Roman numerals!

 Can help determine the charge of a multivalent metal ion  BEWARE make sure that the charge of your anion is correct!  Example: FeO

 Example - Calcium carbonate!  An ion, such as carbonate, that is composed of more than one atom is a polyatomic ion  Compounds with polyatomic ions are called ternary compounds instead of binary compounds

 Pretty much the same thing! StepsExample – Aluminum Carbonate 1. Using the periodic table and a table of common polyatomic ions, identify each ion and its charge. Aluminum: Al 3+ Carbonate: CO Determine the total positive charge and the total negative charge needed to equal zero. Al 3+ : 2(3+) = 6+ CO 3 2- : 3(2-) = 6- (6+) + (6-) = 0 3. Note the ratio of cations to anions.2:3 4. Use subscripts to show the ratio of ions. Place the atomic ion in brackets if it needs a subscript. Al 2 (CO 3 ) 3

 Ammonium Sulfate