Obtain a sample of pure KHP from the dispensing area. Using a rough balance, shake about 2 grams into a clean, dry, weighing bottle. Do NOT insert anything into the dispensing bottles of KHP . If the material won't pour, ask your teaching assistant for help. Boil about 500 mL of deionized water to remove dissolved CO 2 .
Hot water is a burn hazard.
Weigh out precisely on the analytical balance two samples of your dried KHP the size you calculated. As the endpoint is approached, more swirling is required. At this point, the solution must be thoroughly mixed and any solution spattered onto upper surfaces of the flask should be washed down with a few ml of deionized water. The endpoint is reached if the solution is still pink after thorough mixing. Repeat this titration with your other sample and calculate the NaOH concentration.