Naming and Writing Formulas for Compounds

1. Naming and Writing Formulas for Compounds Unit 4

2. 1. Naming Ionic Compounds

3. Ionic Compound: • Composed of ions • Cations & Anions • Metals & Nonmetals • Cations: • + charge • Metals • + Polyatomic Ions • Anions: • - charge • Nonmetals • - Polyatomic Ions

4. Name the cation (always 1st) • Name the anion – add “ide” ending (always 2nd) • If anion is polyatomic, just use name (no ending) * This is for cations with a single charge (oxidation state)

5. For cations with more than one oxidation state • Name the cation • Add roman numeral to indicate charge of the cation

6. 2. Writing the Formulas for Ionic Compounds

7. Write the cation symbol • Write the anion symbol (or polyatomic formula) • Balance + and – charges so they add to zero

8. 3. Naming and Writing Formulas for Molecular ComPounds

9. 1 – mono 2 – di 3 – tri 4 – tetra 5 – penta 6 – hexa 7 – hepta 8 – octa 9 – nona 10 - deca • Molecular Compounds • Nonmetals only • Use greek prefixes to tell # of atoms

10. 4. Acids

11. Recognizing an acid • Molecular compound beginning with “H” (or H2 or H3) • May contain polyatomic ions

12. Binary Acids • Start name with “hydro” • Use anion name adding “ic” ending • End with “acid”

13. Oxyacids • Use polyatomic ion name • Add “ic” in place of “ate” • Add “ous” in place of “ite” • End with “acid”

14. Writing Acid Formulas 1. Write the symbol for hydrogen 1st 2. Write the symbol for nonmetal or polyatomic anion 3. Balance + and – charges so they add to zero • (H will have a charge of +1)

15. 5. Diatomic Molecules

16. 2 of the same atom bonded together • Some elements naturally exist as diatomic H, N, O, F, Cl, Br, I

17. 6. Hydrates

18. Ionic salt with molecules of water attached

19. Naming Hydrates • Name the ionic compound • Use a greek prefix for number of water molecules • End with “hydrate”

20. Writing the Formulas for Hydrates • Write the formula for the ionic compound • Indicate the number of water molecules with big number in front of H2O

21. 7. Compounds with Common Names

22. H2O • NaHCO3 • H2O2 • NH3 • CH4 • HCH3COO (HC2H3O2)