Nomenclature (The Process of naming chemicals)

1. Nomenclature(The Process of naming chemicals)

2. Objectives: The student will: -Apply the rules for naming ions and writing the symbols for ions. -Apply the rules for naming and writing formulas for ionic & covalent compounds/molecules.

3. Naming of Ions Monatomic Ions: Ions which consist of one element Cations: positively charged ions retain their name Ex. Na+1  Sodium Ca+2  Calcium Anions: negatively charged ions, the ending of the element adds suffix, “ide” Ex. O-2  Oxide N-3  Nitride

6. Ions of Transition Metals • Transition metals form more than one cation with different ionic charges. • The Stock system is used to name these ions. • A roman numeral in parentheses is placed after the name of the element to indicate the charge. (this # does NOT indicate how many) Examples: Fe+2 = Iron (II) Fe+3 = Iron (III) Cu+1 = Copper (I) Cu+2 = Copper (II)

7. Naming Polyatomic Ions • Polyatomic ions are composed of more than one type of atom/element. • Tightly bound groups of atoms that behave as a unit and carry a charge. Can act as cations or anions. • The names of polyatomic ions usually end in “ite” or “ate” Examples: SO4-2  Sulfate NO2-1  Nitrite MnO4-1  Permanganate

8. Ion Reference Sheet

9. Nomenclature of Ionic Compounds & Covalent Molecules

10. Naming Ionic Compounds(with monatomic ions) • The Metal element, with a positively charged cation, is written first. • The Non – metal element with a negatively charged anion is written second. The ending changes to “ide” Examples: CaCl2 Calcium chloride K2O  Potassium oxide Metal + Non-metal (ide ending) Cation + anion (ide ending)

11. Naming Ionic Compounds(with transition metals) • The Transition Metal element, with a positively charged cation, is written first with the roman numeral indicating charge. • The Non – metal element with a negatively charged anion is written second. The ending changes to “ide” FeCl2 Iron (II) chloride FeCl3  Iron (III) chloride HgBr  Mercury (I) bromide

12. Naming Ionic Compounds(with polyatomic ions) • Write the name of the cation 1st, the name of the anion 2nd. • Use the name of the polyatomic ion as written on the reference sheet. • Remember the polyatomic may be + or -, act as a cation or anion. Na2SO4 Sodium sulfate LiOH  Lithium hydroxide **Hint: Usually when more than one type of element is seen a polyatomic ion exists somewhere. Look carefully!**

13. PRACTICE

14. Writing Formulas for Ionic Compounds • The net charge of the formula must = zero. Cation charge = Anion charge. 2. Read the name, write the symbol with charge for the cation and anion. • Use the Criss - Cross Method to determine subscripts in creating a balanced formula. Subscripts indicate how many of each element is needed. • The charge on one element is the subscript on the other element and vice versa.

15. PRACTICE

16. Naming Covalent Molecules • Molecules between 2 non-metals. • Prefixes are needed to indicate how many of each element. First element • Keeps its element name • Gets a prefix if there is a subscript on it Second element • Use the root of the element name plus the -ide suffix • Always use a prefix on the second element

17. List of Prefixes 1 = mon(o) 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nona 10 = deka

18. N2O5 • CO2 • SiO2 • H2O • Carbon tetrachloride • Dinitrogen trioxide • Carbon monoxide