Naming Compounds

1)  The nometal name of binary compounds (those consisting of only 2 type elements) must end in 'ide'.

    NaCl   =   sodium chloride                 CaO    =  calcium oxide

     K₂S    =   potassium sulfide               AlCl₃   =  aluminum chloride                                       

    Mg₃N₂   =   magnesium nitride               BaBr₂   =  barium bromide                                             

 2) For transition metals, metalloids, or other metals with multiple oxidation states, calculate what that state must be:

    FeCl₂   =  iron (II) chloride       FeCl₃  =  iron (III) chloride                                 

    SnCl₂    =  tin (II) chloride        SnCl₄   =  tin (IV) chloride                                      

    Fe(OH)₃  =  iron (III) hydroxide     Sn(NO₃)₂  = tin (II) nitrate                                 

 Several harder problems show that the oxidation state of the metal must equal that of the nonmetal.

     CuSO₄   =   copper (II) sulfate     (since sulfate is 2- the copper must be +2)

     Ni₃(PO₄)₂   =  nickel (II) phosphate  (phosphate is 3- but the two of them nickel atoms give up 2 electrons each)

Now we need to look at lots of examples.  After you are given the   formula figure out on paper what you think the final chemical name would look like. 

 Problem # 1:    KmnO₄

  potassium permanganate   (potassium's only oxidation state is +1 so no Roman numerals needed)

 Problem # 2:    MgCO₃

   magnesium carbonate

 Problem # 3:    Au₃PO₄

   gold (I) phosphate    (phosphate is 3- so each gold  atom must be a +1)

Problem # 4:      HgCO₃

 mercury (II) carbonate    (carbonate's charge  is 2- so the one mercury must be +2)

Problem # 5:     Cr₃(AsO₄)₂

   chromium (II) arsenate   (the two arsenates gain 6 electrons, so each chromium must lose 2 electrons)

for more practice:  

Page Last Updated: Friday March 02, 2007           Webmaster: Larry Jones                 Pickens County School District