# Ions not attached but included in chemical formula for tartrazine

In some diagrams for tartrazine ($\ce{C16H9N4Na3O9S2}$), I see that $\ce{SO3Na}$ is actually represented as $\ce{SO3^-}$ with a floating $\ce{Na^+}$ next to it. How does this work?

EDIT: Wait, are they just ionicly bonded together?

• That would be a yes to your ionic bond theory ;) – airhuff Oct 19 '17 at 6:36
• Don't worry, there were worse ;) – Mithoron Oct 19 '17 at 16:08