1. The problem statement, all variables and given/known data 6.83 mL of a solution of NaOH is standardized against 3.06 g of potassium hydrogen phthlate (KHC8O4H4). Calculate the concentration of the base. 2. Relevant equations c=n/v M of KHP = 198.201 3. The attempt at a solution Here is what I did. Calculated moles of pottassium hydrogen phthalate 3.06/198.201 = 0.0154 mol. Used the volume of naoh to calculate concentration. c=n/v . c= 0.0154/ 0.00683 c= 2.25 mol/L The answer is 2.15. What have i done wrong?