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 CaCl 2 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 FeCl 3 Na 2 O CaO Fe 2 O 3 NaClO 3 Na 2 CO 3 Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O CaO Fe 2 O 3 NaClO 3 Na 2 CO 3 Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O contains2 sodium ions and 1 oxide ion CaO Fe 2 O 3 NaClO 3 Na 2 CO 3 Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O contains2 sodium ions and 1 oxide ion CaOcontains1 calcium ion and 1 oxide ion Fe 2 O 3 NaClO 3 Na 2 CO 3 Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O contains2 sodium ions and 1 oxide ion CaOcontains1 calcium ion and 1 oxide ion Fe 2 O 3 contains2 iron ions and 3 oxide ions NaClO 3 Na 2 CO 3 Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O contains2 sodium ions and 1 oxide ion CaOcontains1 calcium ion and 1 oxide ion Fe 2 O 3 contains2 iron ions and 3 oxide ions NaClO 3 contains1 sodium ion and 1 chlorate ion Na 2 CO 3 Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O contains2 sodium ions and 1 oxide ion CaOcontains1 calcium ion and 1 oxide ion Fe 2 O 3 contains2 iron ions and 3 oxide ions NaClO 3 contains1 sodium ion and 1 chlorate ion Na 2 CO 3 contains2 sodium ions and 1 carbonate ion Ca(ClO 3 ) 2

Counting Ions: Practice FeCl 3 contains1 iron ion and 3 chloride ions Na 2 O contains2 sodium ions and 1 oxide ion CaOcontains1 calcium ion and 1 oxide ion Fe 2 O 3 contains2 iron ions and 3 oxide ions NaClO 3 contains1 sodium ion and 1 chlorate ion Na 2 CO 3 contains2 sodium ions and 1 carbonate ion Ca(ClO 3 ) 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: Mg 2+ and Br 1- Li 1+ and P 3- Ca 2+ and O 2- Al 3+ and OH 1- K 1+ and SO 4 2-

Ratio Practice Use diagrams to determine how the following combine to form compounds: Mg 2+ and Br 1- MgBr 2 Li 1+ and P 3- Ca 2+ and O 2- Al 3+ and OH 1- K 1+ and SO 4 2-

Ratio Practice Use diagrams to determine how the following combine to form compounds: Mg 2+ and Br 1- MgBr 2 Li 1+ and P 3- Li 3 P Ca 2+ and O 2- Al 3+ and OH 1- K 1+ and SO 4 2-

Ratio Practice Use diagrams to determine how the following combine to form compounds: Mg 2+ and Br 1- MgBr 2 Li 1+ and P 3- Li 3 P Ca 2+ and O 2- CaO Al 3+ and OH 1- K 1+ and SO 4 2-

Ratio Practice Use diagrams to determine how the following combine to form compounds: Mg 2+ and Br 1- MgBr 2 Li 1+ and P 3- Li 3 P Ca 2+ and O 2- CaO Al 3+ and OH 1- Al(OH) 3 K 1+ and SO 4 2-

Ratio Practice Use diagrams to determine how the following combine to form compounds: Mg 2+ and Br 1- MgBr 2 Li 1+ and P 3- Li 3 P Ca 2+ and O 2- CaO Al 3+ and OH 1- Al(OH) 3 K 1+ and SO 4 2- K 2 SO 4

Ratio Practice Use diagrams to determine how the following combine to form compounds: Al 3+ and O 2- Al 2 O 3 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. Pb 4+ and O 2- becomes ?not Pb 2 O 4

Criss-cross But the ratio between the ions must be reduced to lowest terms (and 1s are not written). E.g. Pb 4+ and O 2- becomes PbO 2 not Pb 2 O 4 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 CaCl 2 Li 2 O

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.: NaClis sodium chloride CaCl 2 Li 2 O

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.: NaClis sodium chloride CaCl 2 is calcium chloride Li 2 O

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.: NaClis sodium chloride CaCl 2 is calcium chloride Li 2 O 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(ClO 3 ) 2 NH 4 F

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.: KOHis potassium hydroxide Mg(ClO 3 ) 2 NH 4 F

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.: KOHis potassium hydroxide Mg(ClO 3 ) 2 is magnesium chlorate NH 4 F

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.: KOHis potassium hydroxide Mg(ClO 3 ) 2 is magnesium chlorate NH 4 F 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. FeOmust be Fe 2 O 3 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. FeOmust beiron (II) oxide (because oxide is O 2- ) Fe 2 O 3 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. FeOmust beiron (II) oxide (because oxide is O 2- and the ratio is 1:1) Fe 2 O 3 must beiron (III) oxide

Names with Multivalent Ions Try it with copper: CuCl 2 CuSO 4 Cu 2 O

Names with Multivalent Ions Try it with copper: CuCl 2 copper (II) chloride CuSO 4 Cu 2 O

Names with Multivalent Ions Try it with copper: CuCl 2 copper (II) chloride CuSO 4 copper (II) sulphate Cu 2 O

Names with Multivalent Ions Try it with copper: CuCl 2 copper (II) chloride CuSO 4 copper (II) sulphate Cu 2 Ocopper (I) oxide

More Practice Please complete the “More Practice” handout and textbook questions p. 171 #6-8.