Chapter 6: Writing and Naming Compounds

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Chapter 6 Writing and Naming Compounds

• A. Writing Ionic Compounds
• Cation positively () charged ion
• - metals
• Anion negatively (-) charged ion
• - non-metals
• - poly-atomic ions
• Poly-atomic ion multiple atoms with a charge
• - most are negative ions
• - on the back of your P.T.
• Ionic compound cation and anion together
• - metal and non-metal

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• Monatomic ions
• ex.

Group 1 213 14 15 16 17
18 Charge 1 2 3 ?4 -3
-2 -1 0
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• Forming ionic compounds
• Use the criss-cross method
• Cross the s only, not the or charges
• s become subscripts (little s below)
• Reduce subscripts (if possible)
• Overall charge of compounds are neutral
• (Poly-atomic ions) keep in parentheses
• ex. Al3 and O2 ? Al2O3
• Ca2 and S2 ? Ca2S2 ? CaS
• Mg2 and NO3 ? Mg(NO3)2

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• B. Naming Ionic Compounds
• Ionic cation and anion
• - metal and non-metal
• Binary 2 elements
• Ternary 3 elements (involves a poly-atomic ion)
• 3 ways to name ionic compounds
• Binary
• Ternary
• Metals with more than 1 charge (transition
  metals) use the back of the P.T.

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• Naming Binary Ionic Compounds
• Name cation (metal) in full
• Name anion (non-metal), but change its ending to
  -ide
• The of atoms (subscripts) do not matter!
• ex. K3N Potassium Nitride
• CaS Calcium Sulfide
• MgCl2 Magnesium Chloride
• Strontium Bromide SrBr2

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• Naming Ternary Ionic Compounds
• Name cation (metal) in full
• Name anion (poly-atomic ion) look at the back
  of the P.T.
• The of atoms (subscripts) do not matter, unless
  it changes the poly-atomic ion!
• ex. NaNO3 Sodium Nitrate
• NaNO2 Sodium Nitrite
• (NH4)2O Ammonium Oxide
• Barium Phosphate Ba3(PO4)2

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• Naming Ionics Metals w/ More Than 1 Charge
• Name cation (metal) in full, but add its charge
  in the form of a (Roman numeral) look at the
  back of your P.T.
• Name anion (non-metal or poly-atomic ion)
• The of atoms (subscripts) of the metal is not
  the Roman number!
• ex. FeI2 Iron (II) Iodide
• FeI3 Iron (III) Iodide
• CuS Copper (II) Sulfide
• Lead (IV) Permanganate Pb(MnO4)4

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• C. Naming Covalent Compounds
• Covalent compounds same thing as molecular
  compounds
• - no ions, but have molecules (2 or
  more atoms together)
• - non-metals only (Hydrogen is a
  non-metal)
• - can be binary or ternary (only
  naming binary)

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• Naming Binary Covalent Compounds
• Use pre-fixes (before elements) to tell how many
  atoms there are
• ex. 1 atom mono
• 2 atoms di
• 3 atoms tri
• 4 atoms tetra
• 5 atoms penta
• 6 atoms hexa
• 7 atoms hepta
• 8 atoms octa
• 9 atoms nona
• 10 atoms deca

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• Naming Binary Covalent Compounds (cont.)
• Name 1st non-metal in full using its pre-fix
• Name 2nd non-metal using its pre-fix, but change
  its ending to -ide
• The of atoms (subscripts) does matter!
• ex. N2Cl Dinitrogen Monochloride
• Si3F6 Trisilicon Hexafluoride
• Disulfur Octabromide S2Br8

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• Naming Binary Covalent Compounds (cont.)
• Exceptions
• If the 1st non-metal has only 1 atom, mono is
  not written
• ex. SO2 Sulfur Dioxide
• Since the pre-fix ends in a vowel and if the
  non-metal starts with a vowel, drop the last
  vowel of the pre-fix (except for di- and tri-),
  then add the non-metal name
• ex. CO Carbon Monoxide
• N2O4 Dinitrogen Tetroxide