What is the balanced net ionic equation for #H_3PO_4(aq) + Ca(OH)_2(aq) -> Ca_3(PO_4)_2(aq) + H_2O(l)#?
Firstly, balance your equation:
Then, split up your aqueous substances into their respective ions:
Then we cancel ions that appear on both sides of the equation: these are spectator ions that do not participate in the reaction.
And write out the new net ionic equation that excludes these ions:
And by cancelling down coefficients we get:
Which is the balanced net ionic equation for any neutralisation reaction : the type of reaction we were dealing with in the first place.