Question

We have a volume `[H_3PO_4]-=2.0*N`. If this is to be reacted with an EQUAL volume of sodium hydroxide...what concentration with respect to `[NaOH]` is required?

Answer 1

Well, its `4*N`...........

Explanation:

Phosphoric acid acts as a diacid in aqueous solution....

`H_3PO_4(aq) + 2NaOH(aq) rarr Na_2HPO_4(aq) + 2H_2O(l)`

And so if you got `[H_3PO_4]=2*mol*L^-1`, this is `4*N` with respect to `H_3O^+`. The volume is irrelevant.