# What is the formula for the compound iodous acid (HIO_3)?

$\text{Iodic acid}$ is $H I {O}_{3}$.
And $\text{iodous acid}$ is $H I {O}_{2}$; and $\text{hypoiodous acid}$ is $H I O$. There are more, however, the modern trend is to assign an oxidation state.