You have 10 problems wrapped up here in one post and I'm not about to spend the next hour doing them in step by step fashion for you; however, I can help you through it. First, how much do you know how to do? Which part confuses you.
1. The first thing you must do is to determine where the two equivalence points are (in mL acid added).
2. Va = 0. That's the pure B. Make an ICE chart and calculate H^+ and pH.
3. Va = ? at the first eq point. H^+ at that point is √k1k2.
3. All volumes between 0 and first eq pt is pH = pK2 + log base/acid
4. Va = ? at second eq pt. Make and ICE chart for this and proceed to H^+ and pH.
5. All volumes between 1st and 2nd eq pt is equation in 3; i.e., you have a buffer and the Henderson-Hasselbalch equation applies. pH = pK1 + log base/acid
6. Va = ? from 2nd eq pt onward is just excess HCl.
The dibasic compound B (pKb1 = 4.00, pKb2 = 8.00) was titrated with 1.00 M HCl. The initial solution of B was 0.100 M and had a volume of 100.0 mL. Find the pH at the following volumes of acid added and make a graph of pH versus Va; Va=0, 1, 5, 9, 10, 11, 15, 19, 20, and 22mL.
1 answer
1 answer