Question

A standard KHP solution is made by dissolving 2.12 grams of KHP in 100.00 mL of water. The KHP solution is then titrated with a NaOH solution. It takes 23.12 mL of NaOH to reach the endpoint. What is the concentration of the NaOH?

Answer 1

The concentration of the NaOH solution that was used to titrate the KHP solution is 0.4488 M. This was determined by first calculating the moles of KHP based on its mass and molar mass, and then using the volume of NaOH to find its molarity.

Step-by-step explanation:

In order to determine the concentration of the NaOH solution used to titrate the KHP solution, we use the reaction stoichiometry and the data provided. Potassium hydrogen phthalate (KHP) reacts with NaOH in a 1:1 molar ratio, as shown in the balanced chemical equation:

KHC₈H₄O₄ (aq) + NaOH(aq) → NaKC₈H₄O₄ (aq) + H₂O(1)

We know the molar mass of KHP is approximately 204.22 g/mol, so we can calculate the moles of KHP used in the titration:

moles of KHP = (2.12 g) / (204.22 g/mol) = 0.01038 mol

Since it took 23.12 mL of NaOH to titrate this amount of KHP and the reaction ratio is 1:1, the moles of NaOH is also 0.01038 mol. To find the molarity of the NaOH, we use the formula:

Molarity (M) = moles of solute / volume of solution in liters

Molarity of NaOH = 0.01038 mol / 0.02312 L = 0.4488 M

Therefore, the NaOH solution concentration is 0.4488 M.