The question is: the arsenate ion has the formula AsO4^3-. Write the formula of the corresponding acid that contains this anion. I don't really understand what I need to do. please help!

Answer 1

You're supposed to write the acid. For example, the acid of Cl^- is HCl. The acid of SO4^2- is H2SO4.
Therefore, the acid for AsO4^3- is H3AsO4.

Answer 2

Thank you for your help.

Answer 3

H2AsO4-