Orientation of H and OH

[305920501]

Why in (HPO4)2- are Oxygen and Hydrogen labeled as one entity (OH) on the Lewis Diagram bonded with a single bond to P (with two lone pairs on the O), while in HClO3, Chlorine is bonded to Oxygen (with two lone pairs on the O) by a single bond, and Hydrogen is bonded to that Oxygen by another single bond? I reviewed the slides from discussion that include illustrations of both these Lewis structures, but I can't figure out why the relationship is displayed differently and without a bond in between H and O in (HPO4)2-.

[Ashley Peterson 2C]

Hello!
To answer your question, I think the main takeaways are that
In (HPO4)2-, the central atom (phosphorous) is bonded to the four atoms in a tetrahedral arrangement and each oxygen atom will form a single bond with the phosphorous atom.
I think this arrangement is why oxygen and hydrogen are labeled as one entity. ^

In HClO3, chlorine is bonded to three oxygen atoms in a trigonal pyramidal arrangement and each oxygen atom will form a single bond with chlorine.

I hope this helps!