Giving the IUPAC name for Al2(Cr2O7)3 ?

[nukeman]

Homework Statement

I don't understand how to do this. There is 2 of them I am not sure of?

1st: As2S3 - Is the correct IUPAC name: DiAresenic Trisulfide?

2nd: Al2(Cr2O7)3 - IS it DiAluminum ... Need help with this. How do you get the IUPAC name from this. Any help would be great!

Homework Equations

The Attempt at a Solution

 

[Jasoni22]

1. Since we know sulfur is in a -2 oxidation state, that means arsenic is +3. So you could call it either arsenic trisulfide or arsenic (III) trisulfide.

2. Aluminum is always +3, and dichromate is always -2, so the name is aluminum dichromate.

 

[nukeman]

I am still having trouble with As2S3

How do we know sulfur is in a -2 oxidation state? And how does Arsenic get a +3

How does that turn into Arsenic Trisulfide?

Really appreciate help on this! Thanks.

 

[Infinitum]

Try this,

http://www.chemguide.co.uk/inorganic/redox/oxidnstates.html