 We're going to add 50 milliliters of our unknown concentrated hydrochloric acid. We want to make sure that we have exactly 50 milliliters. We have a stirring magnet in the Erlenmeyer, and we're going to set it here on our stirring hot plate. We're going to put our standardized sodium hydroxide 0.0998 molar concentration in our burette. Now what I'm going to do is to let out a little bit of the excess so that I know exactly how much is in my burette. This little burette reading card helps you line up the bottom of the meniscus so you can read it every time. Alright, you can see that we have the CBL and the calculator connected to our pH probe. Now you should remember from our earlier video on how to calibrate the probe. We've already calibrated our pH probe, and we're going to select Apps and ChemBio, and we want to collect data. Now in a titration what you do is you add a small amount of one of the solutions and then you record the pH. And the way our CBL and calculator assume to do that is trigger prompt. So you want to select trigger prompt and you can see that it's now ready to collect data. Now that we have our instruments ready and we have our unknown solution in our Erlenmeyer, we're going to add 50 milliliters of water. We're also going to add a couple of drops of phenethylene. This is not necessary since we're using a pH probe, but it is a good colorful indicator. You can see that it's clear. Now we want to add the pH probe to our solution. And you can see that the pH probe has the very tips immersed in our solution. You can see here that it says monitor CBL, press trigger to collect data. So what you do is you look at the CBL and when the numbers stop changing or if they just vacillate from one to the other. When that's true we press trigger. And then you can see our calculator asks us to put a value. Since we have added no sodium hydroxide we'll put zero and press enter. And it says more data are stopped and we want to collect more data. Now that we have our first data point we want to add one milliliter of sodium hydroxide to our solution. We press trigger, I'll enter one and then I want more data. And now we go back and add another milliliter. We've added two milliliters and we want to collect more data. We're adding one more milliliter, trigger. We have now added a total of three milliliters so we press enter and we want to collect more data. Now we have finished our titration and you can see that it's beginning to level off at the very top. So now you can take this data and determine the concentration of our unknown acid.