Molecular Compounds

1. Molecular Compounds Writing names and Formulas (p. 212 – 213)

2. Molecular compounds • formed between nonmetals • smallest electrically neutral unit of the molecular compound that still has the properties of the molecular compound is a molecule

3. Learning Check Indicate whether a bond between the following would be 1) Ionic 2) covalent ____ A. sodium and oxygen ____ B. nitrogen and oxygen ____ C. phosphorus and chlorine ____ D. calcium and sulfur ____ E. chlorine and bromine

4. Solution Indicate whether a bond between the following would be 1) Ionic 2) covalent 1 A. sodium and oxygen 2 B. nitrogen and oxygen 2 C. phosphorus and chlorine 1 D. calcium and sulfur 2 E. chlorine and bromine

5. For ionic compounds, charges are used to determine how many atoms of each element will combine. • For molecular compounds, the prefixes in the name indicates the number of atoms.

6. Molecular Nomenclature (binary compounds) 1. Less e-neg atom usually written first. • Add prefixes to indicate # of atoms. Omit mono- prefix on first element. 3. No double vowels when writing names (oa oo) 4. Change the ending of the second element to -ide.

7. PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER 1 2 3 4 5 6 7 8 9 10 Molecular Nomenclature

9. Learning Check CO carbon ______oxide CO2 carbon _______________ PCl3 phosphorus _______chloride CCl4 carbon ________chloride N2O _____nitrogen _____oxide

10. Solution CO carbonmonoxide CO2 carbondioxide PCl3 phosphorustrichloride CCl4 carbontetrachloride N2O dinitrogenmonoxide

11. Learning Check A. P2O51) phosphorus oxide 2) phosphorus pentoxide 3) diphosphorus pentoxide B. Cl2O71) dichlorine heptoxide 2) dichlorine oxide 3) chlorine heptoxide C. Cl2 1) chlorine 2) dichlorine 3) dichloride

12. Solution A. P2O53) diphosphorus pentoxide B. Cl2O71) dichlorine heptoxide C. Cl2 1) chlorine

13. Molecular Nomenclature • arsenic trichloride • dinitrogen pentoxide • tetraphosphorus decoxide • AsCl3 • N2O5 • P4O10

14. Molecular Nomenclature • SF6 • sulfur hexafluoride

15. Name These • NO2 • CBr4 • BaCl2

16. Write formulas for these • nitrogen trioxide • Carbon tetrahydride • phosphorus trifluoride • aluminum chloride