Naming The Formula CrBO₃


Naming The Formula CrBO3

Name the formula CrBO3.  In order to name the compound, the ions in it must be identified. By referring to a typical common cation and anion list, three likely ions can be found: chromium(II), chromium(III) and boride. They are Cr+2, Cr+3 and BO3-3. This allows for two separate chromium and boride compounds. Namely chromium(II) boride and chromium(III) boride The process can be visualized as follows:

chromium(II) boride       chromium(III) boride

   (Cation)x(Anion)y         (Cation)x(Anion)y

   (Cr+2)x(BO3-3)y           (Cr+3)x(BO3-3)y

Cross over the ion charges to produce the subscripts:

   (Cr+2)3(BO3-3))2           (Cr+3)3(BO3-3)3

Reduce the subscripts to the lowest ratio:

   (Cr+2)3(BO3-3)            (Cr+3)1(BO3-3)1

Remove the charges since the are no longer needed:

   (Cr)3(BO3)2                       (Cr)1(BO3)1

Do not show subscripts that are “1”:

   (Cr)3(BO3)2                         (Cr)(BO3)

Cr is not polyatomic, parenthesis are not needed. Boride is polyatomic and needs parenthesis, if its sub script out side the parenthesis is “1” or bigger.

   Cr3(BO3)2                              CrBO3

The name for CrBO3 is chromium(III) boride.


© Pat Thayer 2014-2016