2. Covalent (Molecular) Compounds *A covalent bond is a chemical bond in which two or more electrons are shared by two atoms. All are formed from two or more nonmetals.

3. Properties of Covalent (Molecular) Compounds Usually gases or liquids (made of molecules) Low melting and boiling points. Poor electrical conductors in all phases. Many soluble in non-polar liquids but not in water.

4. Naming Molecular Compounds CH 4 methane BCl 3 boron trichloride CO 2 Carbon dioxide Methane CH 4

5. Molecular (Covalent) Nomenclature for two nonmetals Prefix System (binary compounds) 1.Less electronegative atom comes first. 2.Add prefixes to indicate # of atoms. Omit mono- prefix on the FIRST element. 3.Change the ending of the second element to -ide.

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

7. CCl 4 N 2 O SF 6 carbon tetrachloride dinitrogen monoxide sulfur hexafluoride Molecular Nomenclature: Examples

8. arsenic trichloride dinitrogen pentoxide tetraphosphorus decoxide AsCl 3 N 2 O 5 P 4 O 10 More Molecular Examples

9. Learning Check Fill in the blanks to complete the following names of covalent compounds. CO carbon ______oxide CO 2 carbon _______________ PCl 3 phosphorus _______chloride CCl 4 carbon ________chloride N 2 O_____nitrogen _____oxide

10. Learning Check 1.P 2 O 5 a) phosphorus oxide b) phosphorus pentoxide c) diphosphorus pentoxide 2.Cl 2 O 7 a) dichlorine heptoxide b) dichlorine oxide c) chlorine heptoxide 3. Cl 2 a) chlorine b) dichlorine c) dichloride

11. Mixed Review Name the following compounds: 1. CaO a) calcium oxideb) calcium(I) oxide c) calcium (II) oxide 2. SnCl 4 a) tin tetrachlorideb) tin(II) chloride c) tin(IV) chloride 3. N 2 O 3 a) nitrogen oxide b) dinitrogen trioxide c) nitrogen trioxide

12. Solution Name the following compounds: 1. CaO 2. SnCl 4 3.N 2 O 3 a) calcium oxide c) tin(IV) chloride b) Dinitrogen trioxide

13. Mixed Practice 1.Dinitrogen monoxide 2.Potassium sulfide 3.Copper (II) nitrate 4.Dichlorine heptoxide 5.Chromium (III) sulfate 6.Iron (III) sulfite 7.Calcium oxide 8.Barium carbonate 9.Iodine monochloride

14. Mixed Practice 1.BaI 2 2.P 4 S 3 3.Ca(OH) 2 4.FeCO 3 5.Na 2 Cr 2 O 7 6.I 2 O 5 7.Cu(ClO 4 ) 2 8.CS 2 9.B 2 Cl 4

15. Now it’s Study Time DONE