In this example, we begin with a 0.03 molar of vitonic acid and a PH of 3.5 or 25 degrees Celsius. We want to find the hydroxide concentration as well as the PKA of our botanic acid. Now, we'll find this guy first. So, in step one and three, I find that PKA. And step two, I find the hydroxide filtration. So let's skip to step two.