A buffer contains 0.10 mol of acetic acid and 0.13 mol of sodium acetate in 1.00 L. (a) What is the pH of this buffer?

Video transcript

Hello everyone today. With the following question, calculate the Ph of a buffer consisting of 0. 30 moles of propane OIC acid and 300. 60 moles of sodium pro pana weight in one leaders, the PK of pro pro pen OIC acid is 4.87. So the first thing I wanna do is we want to calculate the polarity for each of these. So first we'll have our pro propane OIC acid Similarity is simply going to be the moles over the over the volume. So for this, we have .130 moles and we have one leader. This is going to result in 0.130 moller And then our concentration from our propane await. Our study on channel eight is going to follow a similar Manner. We're going to take the moles .160 moles and divided by the volume which is one leader giving us .160 moller. So now we have our polarities or concentrations. No, something that we can note is that the concentration of our sodium is going to be equal to our concentration of our propane weight by itself. And so this is because they come together and they form that .160 moller. So therefore, we can use the chemical equation that we have our sodium pro panel weight dissociating to form sodium ions. And Our Pro Panel eight Ion. Furthermore, we're gonna have our prop anolik acid C three H 602 Plus Our Water. And that's going to form propane away as well plus hydro ni um ions. And so the given combination of propane OIC acid and sodium pro panel is a buffer because we have a weak acid in pro pan OIC acid and its conjugate base. And so whenever we have a buffer, we can simply use the Henderson Hasselbach equation. And that is that the PH is equal to the PK plus the log of our conjugate base divided by our acid. And so we're simply going to plug in the values that we have. It was said that we had a PKA of 4.87. We're going to have a log of our conjugate base, which was the C three H 502 minus, which was the pro panel eight. And that concentration was 80.1 60 moller. And that's gonna be divided by the initial acid That produced it, which is going to be the pro panel, weak acid, which is 0.130 moller. Simplifying this, we are going to get a ph of 4.96 as our final answer. And with that, we have answered the question overall, I hope this helped. And until next time.