What is the net ionic equation for the reaction between phosphoric acid and sodium hydroxide?

I came up with
\begin{align} \tag1 \ce{H+ + H2PO4- + OH- &-> PO4^3- + H2O},\\ \tag2 \ce{H+ + OH- &-> H2O}. \end{align}

Or is it, since phosphoric acid is a triprotic acid, whose ionization is $$\ce{H3PO4 <=>3H+ + PO4^3-},$$ therefore the net ionic equation will be $$\ce{3H+ + 3OH- -> 3H2O}?$$


Phosphoric acid dissociates into hydrogen ions and $\ce{H2PO4^-}$ ions in water. This then can dissociate further, but $\ce{H^+}$ and $\ce{H2PO4^-}$ are the primary ionic species you'd find in a phosphoric acid solution.

$\ce{NaOH}$ dissociates completely into $\ce{Na^+}$ and $\ce{OH^-}$ ions.

The reaction would then be between $\ce{H^+}$ and $\ce{OH^-}$, your option 2.

The difficulty arises because adding more $\ce{NaOH}$ to the reaction pulls off the second then the third hydrogen from the phosphoric acid. In all cases it is an $\ce{H^+}$ reacting with an $\ce{OH^-}$ ion with the phosphate ions as spectators, but that really doesn't tell the story of the reaction well. This is a case where the net ionic equation really isn't your best option.emphasized text


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