Question

In a titration, 25.0 mL of 0.500 M KHP is titrated to the equivalence point with NaOH. The final solution volume is 53.5 mL. What is the value of M1 for the reaction?

Answer 1

The chemical reaction involved in this titration process would be:

NaOH(aq) + KHC8H4O4(aq) = KNaC8H4O4(aq) + H2O(l)

To determine the concentration of the NaOH solution, we, first, need to calculate the moles of NaOH that is used up in the reaction given the amount of KHP solution that is used. We do as follows:

Moles NaOH = 0.500 M KHP ( .025 L solution ) ( 1 mol NaOH / 1 mol KHP ) = 0.0125 mol NaOH reacted

Volume of NaOH solution used = 53.5 mL - 25.0 = 28.5 mL

Molarity is the number of moles of a solute per liter of solution. We calculate as follows:

Molarity of NaOH = 0.0125 mol / .0285 mL = 0.44 M