Potassium hydrogen phthalate, abbreviated KHP, is used to standardize NaOH solutions. 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 NaOH solution. It takes 23.12 mL of NaOH to reach the endpoint. What is the concentration of the NaOH?