Question

Calculate the volume, in milliliters, of a 0.216 M NaOH solution that will completely neutralize each of the following: 1.) 3.71 mL of a 1.32 M HNO3 solution. 2.) 8.10 mL of a 0.800 M H3PO4 solution.

Answer 1

1)   NaOH + HNO3 -------------> NaNO3 + H2O

    Then,

      n1 = coefficeint of NaOH in the balnced equation

         n2= coefficeint of HNO3 in the balnced equation

          moles of NaOH = moles of HNO3

             M1V1/ n1 = M2V2/ n2

          0.216 M X V1 / 1 = 1.32 M x 3.71 mL/ 1

               V1 = 22.6 mL

Therefore,

     volume of NaOH required for neutralization = 22.6 mL

2)   3NaOH + H3PO4 ---------------> Na3PO4 + 3H2O

Therefore,

          n1 = coefficeint of NaOH in the balnced equation

         n2= coefficeint of H3PO4 in the balnced equation

      moles of NaOH = moles of H3PO4

        M1V1/n1 = M2V2/n2

        0.216 M x V1/3 = 0.8 M x 8.10 mL / 1

        V1 = 90 mL

Therefore,

         volume of NaOH required for neutralization = 90 mL