ml calibration marks then record the initial buret reading 3. Open the stopcock and allow between 10 and 12 ml of water to drain, then record this final buret reading (Calculate the volume of water you dispensed into the beaker by subtracting your intial from your final reading) 4. Drain all the water from the buret into the beaker and pour the water into the drain Filling the Buret for a Titration 1. Obtain about 125 ml of NaOH solution in a clean, dry 250 ml Erlenmeyer flask and stopper the flask with a clean cork 2. Remove the buret from the clamp and rinse the buret with 5 ml of NaOH then repeat 3. Rinse the funnel with NaOH solution then fill the buret with NaOH solution to a point above the 0 ml calibration 4. Eliminate any air bubbles in the tip by rapidly rotating the stopcock a few times, then slowly drain the NaOH solution into the beaker until it is slightly below 0 ml Preparing the KHP Sample 1. Obtain about 7 grams of KHP in a dry vial 2. Weigh a piece of weighing paper. Record the mass of the paper. 3. Transfer between 2.9 to 3.1 grams of KHP onto the weighing paper. Record the mass of the paper and the KHP. 4. Pour the KHP into a 125 ml Erlenmeyer flask and add about 40 ml of distilled water. Gently swirl the flask until the KHP dissolves 5. Add 3 drops of phenolphthalein solution to the KHP solution
Titrating the KHP 1. Read and record the initial buret reading. 2. Position the flask containing the KHP solution under the buret 3. Titrate the KHP solution and record the final buret reading 4. Pour the titration mixture into the sink and rinse out the Erlenmeyer flask with tap water and then distilled water 5. Refill the buret with NaOH solution and repeat steps 1-3 6. Drain the NaOH solution into the “Discarded solutions” beaker and rinse the buret twice with distilled water 7. Return any unused KHP to your lab instructor Neutralizing your discarded solutions 1. Add 2 to 3 drops of phenolphthalein solution to the “Discarded solutions” beaker.
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