1 Monday, December 8th Warm-Up Draw the Lewis Dot Structure for Carbon Monoxide. What is the molecular formula for Dinitrogen trioxide? Draw the Lewis Dot Structure for C 2 H 4. Pick up all four handouts, a periodic table, and a few colored pencils

2 Ionic Compounds and Bonding 4 Different Types of Bonds 1. Covalent Bonds 2. Ionic Bonds 3. Metallic Bonds 4. Hydrogen Bonds

3 What is an ion? An ion is an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

4 What is an ionic compound? Ionic compounds are simply compounds made of ions and joined by an ionic bond.

5 Ionic Compounds Characteristics of ionic compounds  The charges of ionic compounds are balanced (the positive charges equal the negative charges).  They form crystalline structures.  Have high boiling and melting points.  Dissolve in water easily.  Most ionic compounds are between metals and non-metals.

6 Ionic Bonds An ionic bond is a bond formed by the attraction between two oppositely charged ions.

7 Nomenclature Monatomic: prefix “mono” from the Greek word “monos” meaning “ONE” Examples: Na + Cl - Ca 2+ O 2- Polyatomic: prefix “poly” from the Greek word “polys” meaning “MANY” Examples: NH 4 + H 2 PO 3 2- SO 4 2-

8 Nomenclature Binary Compound: prefix of “bi” from the Latin word “bis” meaning “two” or “twice” Examples: NaCl MgO KI

9 Binary Compounds Contain a metallic cation and a nonmetallic anion. Example: CaF 2 & Electron Configuration

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11 Ionic Compounds A formula unit is the chemical formula for an ionic compound. i.e. “NaCl” for Sodium Chloride

12 Oxidation Numbers The oxidation number of an element in a compound equals the number of electrons transferred from the atom to form the ion. Example: NaCl

13 Oxidation Numbers The transition metals and Families 13 & 14 can have more than one oxidation number, or ionic charge For instance, Iron can be Fe 2+ or Fe 3 +

14 Oxidation Numbers

15 Formulas for Binary Compounds Cation, then Anion Na+ is the Cation, Cl- is the anion So, it is “NaCl” not “ClNa”

16 Formulas for Binary Compounds Remember: the charge of an ionic compound is zero. If you add the oxidation number of each ion in a compound multiplied by the number of those ions, the total must be zero. Example: compound containing both sodium and fluorine atoms

17 Formulas for Binary Compounds Determine the formula for the ionic compound formed from potassium and oxygen.

18 Formulas for Binary Compounds Determine the formula for the ionic compound formed by aluminum ions and sulfide ions.

19 Formulas for Binary Compounds Name the following: Na 2 S Li 2 O Write the formula for the following: Potassium sulfide Aluminum oxide

20 Polyatomic Ionic Compounds Polyatomic ionic compounds are compounds made up of two or more different ions. Examples: NH 4 + HCO 3- SO 3 2- HPO 4 2-

21 Polyatomic Ions Polyatomic ions exist as a single unit, so never change the subscripts of the atoms If more than one polyatomic ion is needed, place parentheses around the ion and write the appropriate subscript outside the parentheses. (PO 4 3- ) 2 (ClO 4 - ) 4

22 Polyatomic Ions Write the formula for the compound formed by NH 4 + and O 2-.

23 Polyatomic Ions A compound formed by calcium ions and phosphate ions is often used in fertilizers. Write the compound’s formula. Use your “Polyatomic Sheet” handout to help

24 Polyatomic Ions Write the formula for the ionic compound formed by sodium and nitrate.

25 Naming Polyatomic Ions An oxyanion is a polyatomic ion composed of an element (usually a non-metal) bonded to one or more oxygen atoms. More than one oxyanion usually exists for some non-metals like Nitrogen and Sulfur.

26 Naming Polyatomic Ions The polyatomic ion with the greatest number of oxygen atoms will end in –ate The polyatomic ion with the lesser number of oxygen atoms will end in –ite NO 3 - NO 2 - SO 4 2- SO 3 2-

27 Naming Polyatomic Ions Some elements will form four oxyanions, not just two. So what do we call those? The oxyanion with the greatest number of oxygen atoms is named with the prefix per-, the root of the non-metal, and the suffix –ate ClO 4 perchlorate BrO 4 perbromate

28 Naming Polyatomic Ions The oxyanion with one fewer oxygen atom uses the root of the non-metal and the suffix –ate ClO 3 - chlorate The oxyanion with two fewer uses the root of the non-metal and –ite ClO 2 - chlorite

29 Naming Polyatomic Ions The oxyanion with the least number of oxygens uses the prefix hypo-, the root of the non-metal, and the suffix –ite. ClO - hypochlorite

30 Naming Polyatomic Ions What is this? Its active ingredient is “sodium hypochlorite” What is the chemical formula for sodium hypochlorite?