Question

Consider the titration of 25.00 mL of 0.300 M H3 PO4 with 0.300 M NaOH.

A. Write the net ionic equation for the reaction of phosphoric acid with NaOH to form sodium phosphate and water:

Answer 1

The reaction is an acid base reaction

note that in these type of reactions, there is an acid + base reacting to form water + respective salt

then, identyify the acid = H3PO4 (due to H ions)

the base must be then NaOH ( due to OH)

the reaction is then:

H3PO4 + NaOH = H2O + Na3PO4

the salt must be Na3PO4 (balanced charges since Na+ and PO4-3)

then

the balance

H3PO4 + 3NaOH = 3H2O + Na3PO4

typically: 1 acid molecule will have 3 moleucles of H+ that must react with other 3 mkolecules of OH-

then we must have 3 molecules per base

that is a 1:3 ratio

finally, add phases

the phases

H3PO4(aq) + 3NaOH(aq) = 3H2O(l) + Na3PO4(aq)

the net ionic:

3H+(aq) +3OH-(aq) = 3H2O(l)

it considers only those species being reacted, that is, H+ and OH-; the salt remains in solution so techinically it is not reacted