Module 4: Part C Binary Molecular Compounds

 Binary Molecular compounds are explained after the ionic compounds in Corwin Chapter 7 section 7.7, and inorganic acids are not covered till last in the chapter.


 The required Online Binary covalent Molecules Homework

The web site is:
C: Binary Molecular Names:

C1: Binary Molecular Formulas:


Here is a brief tutorial for Part C: 


 Both elements are nonmetals attached by covalent bonds.  These bonds may be single, double, or triple covalent.  Due to the covalent bonding there are many ratios of the same two elements making many different compounds.  For this reason, the chemist states how many atoms of each element is present in the chemical formula in the formal name of the compound.

Prefixes are attached to each element to indicate how many.  Each student should learn the following prefixes:

MONO            =          ONE                                        HEXA              =          SIX

DI                    =          TWO                                       HEPTA            =          SEVEN

TRI                  =          THREE                                   OCTA             =          EIGHT

TETRA            =          FOUR                                      NONA            =          NINE

PENTA            =          FIVE                                        DECA              =          TEN

The element that is shown first in the chemical formula is written first using the proper prefix to indicate how may atoms of that element is contained in the compound.  If there is only one atom of that element it is often found without the prefix mono.  If you leave the prefix off then it is understood that you mean mono.

The element which is written second in the chemical formula is written second in the chemical name, but in addition to the prefix indicating how many, the suffix of the elementís name is changed to -ide

 carbon becomes carbide                             chlorine becomes chloride

sulfur becomes sulfide                                oxygen becomes oxide

hydrogen becomes hydride                        nitrogen becomes nitride 

Therefore, the following formulas of binary compounds would be spoken:

CCl4                 carbon tetrachloride                                                     

SO2                  sulfur dioxide

CO2                 carbon dioxide

N2O3                dinitrogen trioxide

 BH3                 boron trihydride

We use common names for NH3, and H2O. What would be their correct binary molecular names? Methane, CH4, is the organic name for CH4, what would its inorganic name be?

 For more practice on Corwin page 189 try problems 43 thru 46 for binary nonmetal compounds.