[antoinetta]

Hi, I just want to clarify what is the proper naming for this:

Cl2O7 - is it dichlorine heptaoxide or heptoxide dichloride?

[english]

Binary covalent compounds are always read from left to right.  The element with the lower group number is the first word and the element with the higher group number is the second word.  The only exeption is when the compound has a halogen; in this case you have chlorine.  Any time you have a halogen in the name it always comes first.

Dichlorine heptaoxide.

If you had CO, it would be carbon monoxide, not carbon oxide.

[antoinetta]

Thanks for your reply.  I just want to clarify because my chem teacher said that both answers are acceptable for this compound.