A 31.0 sample of an unknown H3PO4 solution is tritrated with a 0.120M NaOH solution. The equivalence point is reached when 26.43 mL of NaOH solution is added. What is the concentration of the unknown H3PO4 solution? The neutralization reaction is as follows:H3PO4(aq)+3NaOH(aq)= 3H2O(l)+Na3PO4(aq)