1 Naming Compounds Writing Formulas Ionic and Covalent Compounds

2 Assignments Friday's quiz on writing formulas and naming compounds. Chapter and Chapter 7 - 1, complete section review workbook pages and 53 and 54; DUE Thursday, 11/12/09

3 Assignments Double Bubble Map to C/C the properties of ionic and molecular compounds (see chapter 6 -2 and 3) Due Tuesday Describe such characteristics as the strength of forces of attraction, melting point, boiling point, hardness, and solubility. Account for the differences between the two types of compounds. Describe such characteristics as the strength of forces of attraction, melting point, boiling point, hardness, and solubility. Account for the differences between the two types of compounds.

4 Naming Compounds Writing Formulas Write down 3 things you can tell about these substances from their formulas. Which one is ionic? MgCl 2 CCl 4

5 Systematic Naming Compound is a substance made of two or more elements. Name should tell us how many and what type of atoms.

6 Systematic Naming MgCl 2 CCl 4 Formula tells which and how many atoms ; type bond formed Mg – Magnesium – 1 atom Cl – Chlorine – 2 atoms metal + nonmetal = ionic C – Carbon – 1 atom Cl – Chlorine – 4 atoms Nonmetal + nonmetal = molecular compound

7 Systematic Naming Binary Compounds – 2 elements Ternary Compounds – 3 or more elements

8 Two Types of Compounds 1. Ionic Compounds Metals and nonmetals. The electrons lost by the cation are gained by the anion. Smallest piece is a FORMULA UNIT.

9 Two Types of Compounds 2. M olecular compounds Made of molecules. Made by joining nonmetal atoms together into molecules. Sometimes hydrogen

10 1. Ionic Compounds Cation – positive ion; Cation – positive ion; Lose electronsLose electrons Anion – negative ion; Anion – negative ion; Gain electronsGain electrons

11 What type ion would form? LithiumFluorine LithiumFluorine Beryllium Sulfur Beryllium Sulfur Barium Nitrogen Barium Nitrogen

12 1. Ionic Compounds NA Common Ion Charges

13 1. Ionic Compounds: Naming Cations Cation - if the charge is always the same (Group 1) just write the name of the metal. Most transition metals can have more than one charge. Indicate the charge with Roman numerals in parenthesis. Co 2+ Cobalt (II) ion

14 1. Ionic Compounds: Naming Cations A few, like silver, zinc and cadmium only form one kind of ion Don’t get roman numerals Ag+ silver ion Zn 2+ zinc ion Cd 2+ cadmium ion

15 1. Ionic Compounds: Naming Cations Na1+ Ca2+ Al3+ Fe3+ Fe2+ Li1+ Pb 2+ Sodium ion Calcium ion Aluminum ion Iron (III) ion Iron (II) ion Lithium ion Lead (II)

16 1. Ionic Compounds: Naming Anions Anions are always the same. Change the element ending to – ide F 1- - Fluorine = Fluoride

17 1. Ionic Compounds: Naming Anions Cl1- N3- Br1- O2- Ga3+ Chloride ion Nitride ion Bromide ion Oxide ion Gallium ion

18 Naming Binary Ionic Compounds Putting it all together A cation and an anion. The name is just the names of the ions. Cation first anion second Easy with Group A elements. NaCl = Na+ Cl- = sodium chloride MgBr 2 = Mg2+ Br- = magnesium bromide

19 Naming Binary Ionic Compounds The problem comes with the transition metals. Cation name includes the charge. The compound must be neutral. same number of + and – charges. Use the negative charge to find the charge on the positive ion.

20 Naming Binary Ionic Compounds Write the name of CuO Need the charge of Cu O is 2- Copper must be 2+ Copper (II) Oxide Name CoCl 3 Cl is 1- (three of them) = 3- Co must be 3+ Cobalt (III) chloride

21 Naming Binary Ionic Compounds Write the names of the following KCl Na 3 N CrN Sc 3 P 2 PbO PbO 2 Na 2 Se

22 Naming Ternary Ionic Compounds Will have polyatomic ions At least three elements (3 capital letters) Still just name the ions NaNO 3 CaSO 4 CuSO 3

23 1. Ionic Compounds: Rules Write symbols for each ion side by side. Write cation first. Al 3+ O Crisscross the charge of each ion as the subscript for the other ion. Al 2 3+ O 3 2- ( balance charges= (2 x 3+) - (3 x 2-) = = Reduce the subscripts to give smallest possible ratio of ions Write the formula. Al 2 O 3

24 Writing Formulas The charges have to add up to zero. Get charges on each ion. Cations from name or periodic table. Anions from periodic table or polyatomic ion.

25 Writing Formulas Balance the charges by adding subscripts. Always put polyatomic ions in parenthesis

26 Writing Formulas Write the formula for calcium chloride. Calcium is Ca 2+ Chloride is Cl 1- Ca2+ Cl1- would have a 1+ charge. Crisscross Ca 2+ Cl 1- -Ca 2(+) Cl 1(-) – Ca 2 Cl 1 CaCl 2 Remember 1 is understood

27 Writing Formulas Switch the numerical value of the charges Ba2+N3- Ba 3 N 2 Reduce ratio if possible

28 Molecular Compounds Writing names and Formulas Molecular compounds name tells you the number of atoms. Uses prefixes to tell you the number Page 212