[Bassel]

hi, there is a question in an exam preparatory book that i don't know from which chapter it is

question : An oxide of iron has the formula Fe3O4 and contains both Fe2+ and Fe3+ ions. Which one of the following is the fraction of iron ions that are in the Fe2+ state?

what lesson is that ? i need to know in order to study the chapter.

thank you for your help.

[Hunter2]

Nobody can answer this. Because we don't know which book you talking about.