3.5 - 3.7
Formula Writing (Ionic Compounds)
Steps:
1.) Cation is written before anion.
2.) Charges must cancel. (ionic compounds are neutral)
3.) Atoms must be in smallest whole number ratio.
Write the formula units for the following ionic compounds: 1.)
lithium chloride, 2.) strontium oxide, 3.) ammonium phosphate.
1.) LiCl
2.) SrO
3.) (NH4)3PO4
Naming Ionic Compounds
• We are going to use systematic names, IUPAC rules for naming, rather than
common names.
Steps:
1.) Identify if the metal forms more than one type of ion.
-If it doesn’t, write the name of the metal.
-If it does, figure out which ion you are working with
and write the name of the metal followed by roman
numerals in parenthesis, to indicate the charge on the
metal ion.
2.) Identify the anion.
-If the anion monatomic, you are working with a binary
compound. Here the ending of the anions name is changed to –ide.
-If the anion is polyatomic, write the name of the polyatomic ion.
Let’s Try Naming a Few Ionic
Compound
Name the follow ionic compounds:
1.) AlN
2.) Fe2O3
3.) Na2CO3
4.) Sn(ClO3)2
1.) aluminum nitride
2.) iron(III) oxide
3.) sodium carbonate
4.) tin(II) chlorate
Naming Molecular Compounds
• Again we will use a systematic naming system for
naming molecule.
Steps for naming binary molecules:
1.) Use a prefix for the first element if there is more
than one atom.
2.) Name the first element
3.) Use a prefix for the second element
4.) Name the second element (name ends in -ide)
Let’s Try Naming A Few Binary
Molecules
Name the following molecules:
1.) NO
2.) N2O5
3.) P4S10
1.) nitrogen monoxide
2.) dinitrogen pentoxide
3.) tetraphosphorus decasulfide
Naming Acids
• Acids are molecular compounds that release
hydrogen ions (H+) or hydronium ions (H30+) when
dissolved in water, or hydrogen ion donors.
• There are two types of acids:
1.) binary acid (contains two elements)
ex. HCl (hydrochloric acid)
2.) oxyacids (contains oxygen)
ex. H3PO4 (phosphoric acid)
Naming Acids (continued)
• Binary acid contain a hydrogen and a nonmetal.
– The hydrogen out front becomes hydro– The nonmetal has the ending –ic
– Add acid at the end of the name
• Oxyacids contain a hydrogen and an anion
containing a nonmetal and oxygen.
– For oxyanions that end in –ate, the –ate is changed to –ic
– For oxyanions that end in –ite, the –ite is changed to –ous
– Add acid to the end of the name
Let’s Try Naming a Few
Name the following acids:
1.) HNO2(aq)
2.) HBr(aq)
3.) HC2H3O2(aq)
1.) nitrous acid
2.) hydrobromic acid
3.) acetic acid
Pg. 131 #’s 34, 36, 38, 48, and 54
Read 3.8-3.9 pgs. 107-114