posted by bertie .
Can you please double check to see if i have got this right?
Is the empirical formual for oxide of arsenic As2O5?
Arsenic forms two oxides with oxygen. One is As2O5, the other is As2O3. I'm glad you posted today; please tell your friend you were talking with yesterday (from Scotland) that the data he/she looked at on the other answers, and which he/she was copying to you, shows the formula to be As2O3 and NOT As3O2. I posted a response to that but I'm not sure he/she will see it.
With regard to your problem, if you will post your numbers (mass oxide, mass metal, etc) I can check it in minutes. Thanks.