Binary Compounds Type III

Hi

Cont’d of naming binary compounds. Today, we will learn how to name nonmetals together, which in chemistry is called Type III. First of all, we have to know which elements are nonmetals. All green elements are nonmetals.

The rules are very similar to binary compounds Type I and II

1.     Name the first element, using the full element name

2.     Name the second element with ending –ide

3.     Use prefixes to express numbers of atoms. Do not use mono – in first element

Prefix used to show numbers in chemistry.

Prefix

Mono              1

Di                    2

Tri                   3

Tetra               4

Penta              5

Hexa               6

Hepta              7

Octa                8

Example #1

BF₃ first element is boron B, second element is fluorine F, but according the rule#3 we have to change the ending (–ide) for second element, therefore we have fluoride. Now, B has one atom (we don’t need to indicate the one atom as B_1,) which means mono but as rule # 3 says do not use mono in first element. The second element is F with has 3 atoms, so you have to use prefix tri before the name – trifluride.

The full name for BF3 is boron trifluride.

Example #2

P₂Cl₅;  P = phosphorus, Cl = chlorine. We have 2 atoms of P= diphosphorus, and 5 atoms of chlorine= pentachloride; don’t forget to change the ending for - ide. The full name for P₂Cl₅  is diphosphorus pentachloride