Lab Procedure

SAFETY NOTES: You will be handling strong acids and bases in this lab and must wear goggles at all times. Wash your hands immediately if you get some acid or base on your skin.
Part 1: Standardization of NaOH	In this experiment you are to work in teams of two at each pH meter.
	Obtain about 65-75 mL of NaOH and 30-35 mL of 0.01 M standard HCl. Clean a 50 mL buret and rinse it with the NaOH solution. Fill the buret with the NaOH and record the initial volume and set up a ringstand, short stir bar and flask for titration. Use a utility clamp to suspend a pH electrode on the ring stand.
	Obtain an Orion® pH meter from the stock room. Calibrate the Orion® pH meter for data collection.
	You are now ready to perform the titration. This process goes faster if one person manipulates and reads the buret while the other person records the volume and pH values in both notebooks. Pipet 25.00 mL of standard 0.01 M HCl into a 250 mL beaker. Add a few drops of phenolphthalein to the beaker.
	You are now ready to begin the titration. Your goal in this first titration will be to identify the pH region that surrounds the equivalence point(s). You will do this by consistently adding 2 mL of NaOH and observing the change in pH after each addition. You will continue adding NaOH until you reach a point where the pH no longer changes (> pH 13)
	From the data collected above, you should be able to identify the regions of the titration where the pH changes very slowly and also the region of the equivalence point. You will now repeat the titration. The goal of this second titration is to generate enough data points to create an accurate and smooth curve. Refill the buret if necessary, note the volume and begin the second titration as previously instructed.
	Repeat the Steps above of the procedure using a 15.00 mL sample of phosphoric acid instead of the HCl. Titrate carefully in order to identify the locations of the equivalence point(s).
	Repeat the Steps above of the procedure using a 15.00 mL sample of 7-Up© instead of the HCl. Titrate carefully in order to identify the locations of the equivalence point(s).