Molecular Compounds Covalent Bonds

Molecular Compounds Also called covalent compounds A molecule is a neutral group of atoms that are held together by covalent bonds The valence e- are shared by the atoms Covalent bonding usually occurs between 2 non-metals H2O, CO2, O2, NO

Naming Molecular Compounds Use prefixes 1 mono- 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta- 8 octa- 9 nona- 10 deca-

Examples Tetraphosphorous decoxide Dinitrogen trioxide P4O10 N2O3 As2O5 OF2 Tetraphosphorous decoxide Dinitrogen trioxide Diarsenic pentoxide Oxygen difluoride

Ionic or Covalent Ionic Covalent Ionic Covalent Ionic Ionic Covalent Sodium Bromide NaBr CH4 Fe2O3 CO2 CaO NH4Cl SiCl4 Covalent Carbon tetrahydride Iron (III) oxide Ionic Covalent Carbon dioxide Ionic Calcium oxide Ionic Ammonium chloride Covalent Silicon tetrachloride

Diatomic Molecules H2 O2 N2 Cl2 Br2 I2 F2 7 diatomic molecules No noble gases Halogens and N, O, H They are all gases (not noble gases) except for Br and I “Honcl brif”

Empirical Formula CH3O NaC4H6O2 A formula that represents the lowest integral ratio of atoms of the elements in a compound C2H4, C3H6 and C4H8 all have the same empirical formula: CH2 Examples C2H6O2  NaC4H6O2  CH3O NaC4H6O2

Naming Acids **only binary acids use “hydro” Anion Acid Name Example -ide hydro—ic HCl hydrochloric acid -ite --ous HNO2 nitrous acid -ate --ic HNO3 nitric acid **only binary acids use “hydro”

Try these. . . Sulfuric Acid Hydrofluoric Acid Phosphoric Acid H2SO4 HF H3PO4 H2SO3 H2CO3 HNO3 Hydrofluoric Acid Phosphoric Acid Sulfurous Acid Carbonic Acid Nitric Acid

More Practice. . . CaBr2 Cr(C2H3O2)3 BaSO4 Cu2S SF6 Calcium bromide Chromium (III) acetate Barium sulfate Copper (I) sulfide Sulfur hexafluoride Cr(C2H3O2)3 BaSO4 Cu2S SF6

More Practice. . . Chromium (III) oxalate Mercury (II) cyanide Cr2(C2O4)3 Hg(CN)2 Cu(ClO4)2 ZnC4H4O6 Chromium (III) oxalate Mercury (II) cyanide Copper (II) perchlorate Zinc tartrate

How to Calculate Molar Mass The mass of a compound In order to calculate molar mass (also called molecular weight) you add up the masses of each element in the compound Be aware of subscript numbers that designate the amount of atoms per element You get the masses from the periodic table **be careful when rounding the mass

Examples 58.5 g/mol 18 g/mol 63 g/mol 261.3 g/mol NaCl H2O HNO3 Na = 23 g/mol Cl = 35.5 g/mol H2O H = 1 g/mol (but there are 2) = 2 g/mol O = 16 g/mol HNO3 H = 1 g/mol N = 14 g/mol O = 16 g/mol (but there are 3) = 48 g/mol Ba(NO3)2 Ba = 137.3 g/mol N = 14 g/mol (but there are 2) = 28 g/mol O = 16 g/mol (but there are 6) = 96 g/mol 18 g/mol 63 g/mol 261.3 g/mol