 So now we're actually going to do our titration, but before we do our titration, we actually have to add what is called an indicator that will tell us that our reaction is basically complete. So this indicator's name is actually phenolphthalein, and phenolphthalein, I should say. The concentration I'm using is 0.1%. The importance of this indicator is that in an acid environment it is colorless, but when a base is added, when all of the reaction, when the reaction is complete, the solution is going to turn from colorless to pink. So the indicator is going to tell you when your reaction has ended. And if I didn't mention this before, actually the type of reaction that we're doing is called a neutralization reaction, where an acid plus a base gives you a salt plus water. So when the neutralization point has been reached, the indicator is going to change its color from colorless to pink. So for this reaction, I'm going to use two drops of phenolphthalein, and then I'm going to start my titration. So the burette, in this case, contains the base which we're using, which is actually sodium hydroxide. The flask contains KHB, so just to note, make a note of that. So we already know how much KHB we have in our flask. We added one gram of the solid to 30 ml of water. So we know what we have in our flask. What we don't know is the concentration of our sodium hydroxide, or what we want to determine or confirm the concentration of it. So we're going to start first. So this is how you do a titration normally. Since you don't know how much volume you're going to add to your flask, you have to add your volume starting in increments of one mil. So what I want to do first, though, is to record the reading on the burette. So if you notice, the burette has increments starting from zero at the top to 50 at the bottom. So it increases in increments of one mil from zero to 50. So the further up you go, the less the number will be. So I'm starting at an initial concentration of 10 mils. So that's what I read when I look at the level of the sodium hydroxide, when I read below the meniscus. So I'm going to start. So basically you hold their stopcock in order to regulate the amount of base you're adding to your solution. And as I told you, I'm going to add my base in increments of one mil. So I turn my stopcock to a slightly vertical position in order for the base to get in. So I add and I stop every time I get to a mil downwards. Again I stop and I shake to, I swirl the flask in order to make sure that my two substances are mixing together so that they can react with each other. So I continue to do this. So this is what you would do the first time around. You're going to do this three times. This is called your trial run to give you an idea of how much volume you need to add to your acid in order to end the reaction. And remember the reaction ends when the solution turns from colorless to pink. So I notice that my solution is starting to get pink, but the pink does not stay. So it tells me that I still haven't gotten to my end point yet. So each time it's important for you to keep swirling the flask so that the reactants can get mixed with each other. So if you notice, I got a pink color. And if I were to record this and the pink color actually stayed. So this is a trial run. So I recorded the volume at which I first saw pink and it actually remained. And that is the final volume in this case would be, if I read it from the burette, it would be 31.7 mils. So I can determine the volume of sodium chloride that I added by subtracting the final burette reading from the initial burette reading. So that would be 31.7 mils subtracted from 10 mils. And that would give me 21.7 mils of sodium hydroxide. So of course, if you were to do the next trial, the next two runs, you would be more accurate in subsequent readings because now you know that you added 21.7. So if you were to do this experiment over again, if you're going to repeat it twice, then what you do is to subtract three mils from 21. So 21 minus three would give me about 18.7 mils. So the next time you're doing this titration, what you can do to speed up the process is to add approximately 18 mils of your base sodium hydroxide to your acid solution without having to swirl because you know you won't get to your endpoint yet. When you have added 18 mils, then after that time you add drop-wise your base until the first sign of pink color is seen. And then you record that final volume when you first see that pink color. And that would tell you the accurate volume of your base that's reacted with your acid in the Erlenmeyer flask.