 In this lab, your challenge is to find the Ka for the acid in soda water. So we're going to take 50 milliliters of the soda and add that to our Erlenmeyer flask. We'll also add phenethylene just to give us a visual indicator. And then we will place this pH probe in our Erlenmeyer and put everything under our burette and start the magnetic stirrer. The initial pH of our carbonated water is 4.70. So our initial reading, we have added no sodium hydroxide, so we're going to press zero. We want to collect more data. Add one milliliter of the sodium hydroxide. And we will continue in the same vein until we have collected all the data. Now that we have completed our final addition, look at the final pH and the graph on the calculator. Please take these numbers and construct your own graph and then we'll have a series of questions for you to answer from the data.