CHEMISTRY PART 11 Covalent Compounds

Remember...  Metals want to lose electrons and non-metals want to gain them.  These are ionic bonds.

Covalent Compounds  A compound made of only non-metals  Also called a molecular compound.  Electrons are shared between the atoms to have full valence shells.  Hydrogen counts as a non-metal.

Covalent Compounds  Covalent Compounds Animation Covalent Compounds Animation  Sharing of electrons forms a covalent bond.  Single bond  2 electron shared  Double bond  4 electrons shared  Triple bond  6 electrons shared

Covalent Compounds  Example:  Hydrogen and chlorine both want 1 electron to fill their valence shell.  They will share 1 electron. H now has 2e - in its valence shell and Cl has 8, so they are both full. Indicates a single bond This is the structural formula.

Practice  Draw the structural formula for each covalent compound created from the following pairs of electrons. 1. bromine and iodine 2. nitrogen and chlorine 3. carbon and fluorine 4. sulfur and bromine

Practice AtomsStructural Formula bromine and iodine nitrogen and chlorine carbon and fluorine sulfur and bromine

Practice 1. H 2 O 2. CO 2 3. NH 3 4. SCl 2 5. CH 4 6. C 2 H 6 7. CBr 4 8. CH 2 Cl 2

Practice 1. K and Se 2. C and Cl 3. C and O 4. Sr and Br 5. N and I 6. B and H 7. Ca and N 8. Al and S

Naming Covalent Compounds  Determine if it is a covalent compound:  Is it non-metal and non-metal? 1. Name the first element. Use a prefix if there is more than one. 2. Name the second element. Use a prefix to indicate the number of atoms (even if there is only 1). Add the ending “ide”.

Naming Covalent Compounds Number of AtomsPrefix 1mono- (only used for second element) 2di- 3tri- 4tetra- 5penta- 6hexa- 7hepta- 8octa- 9nona- 10deca-

Practice  Examples:  NO  nitrogen monoxide N2ON2O  dinitrogen monoxide

Practice 1. NO 2 2. CO 3. PI 3 4. SO 2 5. SO 3 6. S 2 F CCl 4 8. N 2 O 5 nitrogen dioxide carbon monoxide phosphorus triiodide sulfur dioxide sulfur trioxide disulfur decafluoride carbon tetrachloride dinitrigoen pentoxide

Formula Writing  Use the prefixes to write the formula.  Example:  phosphorus pentachloride  PCl 5

Practice 1. nitrogen tribromide 2. nitrogen dioxide 3. sulfur pentoxide NBr 3 NO 2 SO 5

Diatomic Molecules  HOFBrINCl  When alone in nature, these elements exist in a diatomic form.  The atoms come in pairs, as gases.  H 2 (g) = hydrogen  O 2 (g) = oxygen  N 2 (g) = nitrogen

Diatomic Molecules  Draw covalent bond diagrams for:  H 2, O 2, F 2, Br 2, I 2, N 2 and Cl 2

Practice  Worksheet  Page 127 # 8, 15