 So the next lab that you'll be doing is a buffer lab. So in this lab you're gonna be learning about buffers, what they are, and how they work basically. So a buffer is basically a solution that resist changes in pH whenever you add a strong acid or a strong base. So a buffer solution normally is made up of a weak acid and a weak base. And the idea is that the weak acid or the weak base can grab ions if you add any acid or base to it so that it won't cause a pH change, drastic pH change. So for example, if you add hydrochloric acid to an acetate buffer solution, the acetate ions are gonna grab the hydrogen ions from the acid that you just added, and this will prevent the excess hydrogen ions from causing the pH to go lower than normal. So the buffer basically acts as a sponge so that it prevents extreme changes in pH whenever the system, the buffer system is altered. So buffers are important in everyday life, especially in our bodies as humans. For example, our blood. Our blood needs to be at a pH of about 7.4. And in order to ensure that that's the case, a buffer system called the bicarbonate, carbonic acid system is there so that any change that occurs to our blood, if there's any acid or any base that is added to the blood system that could cause a drastic change in pH, the buffer system is there to prevent that change. So that's important to know about buffers. So basically the buffer range is a pH range in which the buffer is able to resist those large changes in pH. And normally the buffer range can be determined if you know the disassociation constant of the weak acid that is a component of your buffer. So the disassociation constant here is the pKa. So the buffer range is normally the pKa of the acid plus minus one. So therefore you can get from your textbook the disassociation constant for certain acid and for I should say for the acetate buffer, this is not acetate acid, this is the disassociation constant for the acetate buffer and that pKa value is 4.8. That means that the buffer, the acetate buffer has a range of between 3.8 to 5.8. So if the pH of the buffer is outside of that range, then it will cease to act like a buffer. So if you were to add an acid to a buffer that was let's say outside of the range, the acetate buffer being let's say probably seven, what would happen is that when the space is added, the pH is gonna be drastically increased. Whereas if it was in the range, the addition of sodium hydroxide would cause a very slight change if any. So that is why buffers are important to keep the system in equilibrium. Now another important thing to note for the lab is what is called the buffer capacity and we're gonna be able to calculate that based on the data that we collect from our lab. So it is the number of moles of either an acid or a base that is needed to change one liter of buffer by one pH unit. So this is telling you how much can your buffer contain? What's the capacity of acid or base that you can add to your buffer that will prevent it from causing a drastic change in pH or either an increase or a decrease? So we're gonna know more about that when we do the lab. So basically this is what you're gonna be required to do. You're gonna titrate 125 mils of your acetate buffer with first you're gonna titrate it with one molar hydrochloric acid or one molar sodium hydroxide. And you're gonna collect the data that you're gonna be using. So you're gonna be using your burette. You're gonna add for example, if you're gonna titrate with your sodium hydroxide you're gonna add the base to your acetate buffer which is 125 mils. And each time you add a small amount of your base you're gonna record the pH readings so that you'll get a series of data with increased pH versus increased volume. And based on that you'll be able to plot a titration curve which will show the pH which will be plotted against your volume. So your pH will be on your Y axis. The volume of base added would be on your X axis. And in the case of acid the volume of your acid added would also be on the X axis. And then based on the data that you collect you're gonna be able to calculate the buffer capacity of 125 mils of acetate buffer.