HIO4, also known as periodic acid, doesn't directly ionize into IO3- (iodate) ion. Instead, it ionizes in a stepwise manner, losing protons (H+) to form different anions. Here's how it happens:

Step 1: Formation of IO3-

HIO4 (periodic acid) is a strong acid. In aqueous solutions, it readily loses one proton to form the hydrogen periodate ion (HIO4-):

HIO4 + H2O → HIO4- + H3O+

Step 2: Further ionization (if conditions are favorable)

The hydrogen periodate ion (HIO4-) can further lose a proton in a second ionization step, although this is less likely to occur:

HIO4- + H2O → IO42- + H3O+

Key points:

* HIO4 is a strong acid: This means it readily donates protons to form H3O+ (hydronium ions), making the solution acidic.

* IO3- formation is not a direct ionization: HIO4 doesn't directly produce IO3- ions. It first loses a proton to become HIO4- and then potentially a second proton to become IO42-.

Note: The actual equilibrium and speciation of periodic acid in solution can be complex and depend on various factors like pH, temperature, and concentration. However, the above steps provide a simplified understanding of the ionization process.