1. 22.3 Notes Part D Covalent Formulas & Naming

2. Objectives Write formulas and names for covalent compounds

3. Covalent compounds Made of just nonmetals Share electrons Smallest piece is a molecule Can’t be held together because of opposite charges Can’t use charges to figure out how many of each atom

4. Covalent/Molecular compounds Ionic compounds use charges to determine how many of each element. Molecular compounds name tells you the number of atoms. Uses prefixes to tell you the number

5. Naming Covalent Compounds Prefix element name Prefix element name -ide The last vowel of the prefix is dropped when the second element begins with a vowel as in pentoxide No double vowels when writing names (oa oo) Often the prefix mono- is omitted from the first element when naming

6. Examples Carbon dioxide – CO 2 Dihydrogen monoxide – H 2 O Dinitrogren pentasulfide – N 2 S 5 Tricarbon tetrafluoride – C 3 F 4

7. Name These N 2 O NO 2 Cl 4 O 7 NBr 3 BaCl 5

8. Writing formulas for Covalent Compounds Simply write the chemical symbol Subscript is derived from the prefix  Mono = 1, di = 2, tri = 3, ect

9. Write formulas for these diphosphorus pentoxide tetraiodide nonoxide sulfur hexaflouride Carbon tetrahydride phosphorus trifluoride

10. Hydrates An ionic compound that has water chemically attached to its ions and written into its chemical formula

11. Hydratespg. 708 These same prefixes are used when naming the hydrates previously discussed. The main ionic compound is named the regular way, but the number of water molecules in the hydrate is indicated by the Greek prefix. Chemical formula # H 2 O

12. Hydrates BeBr 2 * 3 H 2 O Calcium nitride hexahydrate

13. In-Class Assignment/Homework 22.3 reinforcement WKT