Ionic Compounds: Names and Formulas

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Ionic CompoundsNames and Formulas

• SNC2D

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Counting Ions

• Sodium chloride or NaCl
• contains 1 sodium ion and 1 chloride ion.
• (Lewis dot diagrams)

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Counting Ions

• However, different ions may form compounds in
  different ratios.
• For example, calcium chloride or CaCl2
• contains 1 calcium ion and 2 chloride ions.
• (Subscripts are added to the symbols in a formula
  if there is more than one of that type of atom.)

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Counting Ions Practice

• FeCl3
• Na2O
• CaO
• Fe2O3
• NaClO3
• Na2CO3
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O
• CaO
• Fe2O3
• NaClO3
• Na2CO3
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O contains 2 sodium ions and 1 oxide ion
• CaO
• Fe2O3
• NaClO3
• Na2CO3
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O contains 2 sodium ions and 1 oxide ion
• CaO contains 1 calcium ion and 1 oxide ion
• Fe2O3
• NaClO3
• Na2CO3
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O contains 2 sodium ions and 1 oxide ion
• CaO contains 1 calcium ion and 1 oxide ion
• Fe2O3 contains 2 iron ions and 3 oxide ions
• NaClO3
• Na2CO3
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O contains 2 sodium ions and 1 oxide ion
• CaO contains 1 calcium ion and 1 oxide ion
• Fe2O3 contains 2 iron ions and 3 oxide ions
• NaClO3 contains 1 sodium ion and 1 chlorate ion
• Na2CO3
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O contains 2 sodium ions and 1 oxide ion
• CaO contains 1 calcium ion and 1 oxide ion
• Fe2O3 contains 2 iron ions and 3 oxide ions
• NaClO3 contains 1 sodium ion and 1 chlorate ion
• Na2CO3 contains 2 sodium ions and 1 carbonate ion
• Ca(ClO3)2

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Counting Ions Practice

• FeCl3 contains 1 iron ion and 3 chloride ions
• Na2O contains 2 sodium ions and 1 oxide ion
• CaO contains 1 calcium ion and 1 oxide ion
• Fe2O3 contains 2 iron ions and 3 oxide ions
• NaClO3 contains 1 sodium ion and 1 chlorate ion
• Na2CO3 contains 2 sodium ions and 1 carbonate ion
• Ca(ClO3)2 contains 1 calcium ion and 2 chlorate
  ions

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Why These Ratios?

• It is the valence electrons that determine how
  these ions combine.
• For example, calcium had 2 valence electrons to
  lose and each chlorine only wants 1. So calcium
  has to find 2 chlorines.

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Mg2 and Br1-
• Li1 and P3-
• Ca2 and O2-
• Al3 and OH1-
• K1 and SO42-

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Mg2 and Br1- MgBr2
• Li1 and P3-
• Ca2 and O2-
• Al3 and OH1-
• K1 and SO42-

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Mg2 and Br1- MgBr2
• Li1 and P3- Li3P
• Ca2 and O2-
• Al3 and OH1-
• K1 and SO42-

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Mg2 and Br1- MgBr2
• Li1 and P3- Li3P
• Ca2 and O2- CaO
• Al3 and OH1-
• K1 and SO42-

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Mg2 and Br1- MgBr2
• Li1 and P3- Li3P
• Ca2 and O2- CaO
• Al3 and OH1- Al(OH)3
• K1 and SO42-

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Mg2 and Br1- MgBr2
• Li1 and P3- Li3P
• Ca2 and O2- CaO
• Al3 and OH1- Al(OH)3
• K1 and SO42- K2SO4

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Ratio Practice

• Use diagrams to determine how the following
  combine to form compounds
• Al3 and O2- Al2O3
• Notice that the quick method of determining the
  formula is to criss-cross the valences

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Criss-cross

• But the ratio between the ions must be reduced to
  lowest terms (and 1s are not written).
• E.g. Pb4 and O2- becomes
• ? not Pb2O4

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Criss-cross

• But the ratio between the ions must be reduced to
  lowest terms (and 1s are not written).
• E.g. Pb4 and O2- becomes
• PbO2 not Pb2O4
• Please complete More Formula Practice.

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• NaCl
• CaCl2
• Li2O

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• NaCl is sodium chloride
• CaCl2
• Li2O

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• NaCl is sodium chloride
• CaCl2 is calcium chloride
• Li2O

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• NaCl is sodium chloride
• CaCl2 is calcium chloride
• Li2O is lithium oxide

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• KOH
• Mg(ClO3)2
• NH4F

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• KOH is potassium hydroxide
• Mg(ClO3)2
• NH4F

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• KOH is potassium hydroxide
• Mg(ClO3)2 is magnesium chlorate
• NH4F

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Ionic Compounds Names

• The name of an ionic compound is simply the name
  of the positive ion followed by the name of the
  negative ion, e.g.
• KOH is potassium hydroxide
• Mg(ClO3)2 is magnesium chlorate
• NH4F is ammonium fluoride

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Names with Multivalent Ions

• The only tricky ones to name are those that
  contain multivalent ions. It is necessary to
  look at how the ions have combined to figure out
  the valence of the multivalent ion.
• FeO must be
• Fe2O3 must be

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Names with Multivalent Ions

• The only tricky ones to name are those that
  contain multivalent ions. It is necessary to
  look at how the ions have combined to figure out
  the valence of the multivalent ion.
• FeO must be iron (II) oxide
• (because oxide is O2-)
• Fe2O3 must be

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Names with Multivalent Ions

• The only tricky ones to name are those that
  contain multivalent ions. It is necessary to
  look at how the ions have combined to figure out
  the valence of the multivalent ion.
• FeO must be iron (II) oxide
• (because oxide is O2- and the ratio is 11)
• Fe2O3 must be iron (III) oxide

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Names with Multivalent Ions

• Try it with copper
• CuCl2
• CuSO4
• Cu2O

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Names with Multivalent Ions

• Try it with copper
• CuCl2 copper (II) chloride
• CuSO4
• Cu2O

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Names with Multivalent Ions

• Try it with copper
• CuCl2 copper (II) chloride
• CuSO4 copper (II) sulphate
• Cu2O

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Names with Multivalent Ions

• Try it with copper
• CuCl2 copper (II) chloride
• CuSO4 copper (II) sulphate
• Cu2O copper (I) oxide

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More Practice

• Please complete the More Practice handout and
  textbook questions p. 171 6-8.