Fundamentals J #9b

[Megan Lu 3D]

For Fundamentals #9b, I was wondering why the weak acid reactant H3PO4 in the neutralization reaction is written in its dissociated form [3H+(aq) + PO4 3-(aq)], as I thought that only strong acids were supposed to be written out as such. For example, the bromous acid (also a weak acid) in part c is written HBrO2. Is there another set of guidelines for determining whether or not to write an acid reactant as dissociated? Thank you!

[Gabby Magat 3F]

I was thinking this too, I'm not sure about Problem J.9b either. I was thinking maybe that we had to write out the dissociation on the left of the equilibrium, but I'm not sure. Another reason may be because you can visualize what happens/see that the H+ from H3PO4 are accepted by NH3, but I don't really know.

If anyone understands how to go about this problem, that would be very helpful!

[Mackenzie Van Val 3E]

I assumed that the reason for writing out the dissociated version of H3PO4 was to see where the H+ goes when it becomes a product- basically, to help us visualize it better. However, looking at it now, I see that the H+ transfers from HBrO2 to H2O in part (c), but the HBrO2 is not written out in a way that would help us visualize that. Therefore, it's odd that one weak acid would be written out in such a way that the other one with a similar dissociation is not. I think this is an interesting thing to point out and I'd also be interested in an answer.