Ionic Compounds: Names and Formulas SNC2D

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

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.)

Counting Ions: Practice FeCl3 Na2O CaO Fe2O3 NaClO3 Na2CO3 Ca(ClO3)2

Counting Ions: Practice FeCl3 contains 1 iron ion and 3 chloride ions Na2O CaO Fe2O3 NaClO3 Na2CO3 Ca(ClO3)2

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

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

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

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

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

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

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.

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-

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-

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-

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-

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-

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

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:

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

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.”

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

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

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

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

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

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

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

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

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

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

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 1:1) Fe2O3 must be iron (III) oxide

Names with Multivalent Ions Try it with copper: CuCl2 CuSO4 Cu2O

Names with Multivalent Ions Try it with copper: CuCl2 copper (II) chloride CuSO4 Cu2O

Names with Multivalent Ions Try it with copper: CuCl2 copper (II) chloride CuSO4 copper (II) sulphate Cu2O

Names with Multivalent Ions Try it with copper: CuCl2 copper (II) chloride CuSO4 copper (II) sulphate Cu2O copper (I) oxide