1. Chapter 7 Section 1 Part 2: Naming Covalent Compounds

2. Naming Binary Molecular Compounds Old system: Old system: –Uses prefixes to indicate number of atoms Prefixes tell number of atoms Prefixes tell number of atoms

3. Naming Binary Molecular Compounds Commonly used prefixes on Table 7-3 page 212 Commonly used prefixes on Table 7-3 page 212 Make sure you know: Make sure you know: –Mono –Di –Tri –Tetra –Penta –Hexa –Hepta –Octa –Nona –Deca

4. Naming Binary Molecular Compounds Rules: Rules: –Less electronegative element given first –Second element has as name: Prefix indicating number of atoms Prefix indicating number of atoms Root name Root name Suffix -ide Suffix -ide –O or A usually dropped at end of a prefix if the element begins with a vowel

5. Naming Binary Molecular Compounds Examples: Examples: –Name PF 5 Phosphorous pentafluoride Phosphorous pentafluoride –Name XeF 4 Xenon tetrafluoride Xenon tetrafluoride –Write formula for carbon dioxide CO 2 CO 2 –Write formula for sulfur hexafluoride SF 6 SF 6

6. Naming Binary Molecular Compounds Sample problem 7-4 Sample problem 7-4 Give the name for As 2 O 5 Give the name for As 2 O 5 –Diarsenic pentoxide Write the formula for oxygen difluoride Write the formula for oxygen difluoride –OF 2

7. Naming Acids Acids: Acids: –Compounds that can donate H+ ions Binary acids: have H and one other nonmetal Binary acids: have H and one other nonmetal Named: hydro-nonmetal root name-ic acid Named: hydro-nonmetal root name-ic acid –Example: HCl Hydrochloric acid Hydrochloric acid

8. Naming Acids Oxyacids: Oxyacids: –Contain H, O and a third element (nonmetal usually) Naming based on polyatomic ion present Most common ion is element-ic acid Less oxygen ion is element-ous acid Even less oxygen ion is hypo-element-ous acid More oxygen ion is per-element-ic acid

9. Oxyacid Naming Example Most common ion with sulfur and oxygen is sulfate ion Most common ion with sulfur and oxygen is sulfate ion –Acid with sulfate ion is sulfuric –H 2 SO 4 Less oxygen than sulfate is sulfite ion Less oxygen than sulfate is sulfite ion –Acid with sulfite ion is sulfurous –H 2 SO 3