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Part 3: Weak-Strong Titrations II. Experiment 2: 20.0 mL of 0.100 M HX (unknown, monoprotic acid)…
Part 3: Weak-Strong Titrations
II. Experiment 2: 20.0 mL of 0.100 M HX (unknown, monoprotic acid) is being titrated with 0.250 M KOH. The Ka has been experimentally determined to be 5.62 x 10-6.
A. Point A: 3.0 mL of the titrant has been added.
1. How many moles of HX are in your initial sample? _____________
2. How many moles of KOH have been added? _____________
4. How many moles of OH– have been added? _____________
5. How many moles of X– have been formed? _____________
(moles X– formed = moles OH– added)
6. How many moles of HX are left over? _____________
(moles HX remaining = initial moles HX – moles X– formed)
7. What is the total volume of the solution after the 3.0 mL addition? _____________
8. What is the concentration of X– in the solution now? _____________
9. What is the concentration of HX in the solution now? _____________
10. What is the pH of the solution now? _____________
(use Henderson-Hasselbalch)
B. Point B: 4.0 mL of the titrant has been added.
1. How many moles of HX are in your initial sample? _____________
2. How many moles of KOH have been added? _____________
4. How many moles of OH– have been added? _____________
5. How many moles of X– have been formed? _____________
(moles X– formed = moles OH– added)
6. How many moles of HX are left over? _____________
(moles HX remaining = initial moles HX – moles X– formed)
7. What is the total volume of the solution after the 4.0 mL addition? _____________
8. What is the concentration of X– in the solution now? _____________
9. What is the concentration of HX in the solution now? _____________
10. What is the pH of the solution now? _____________
(use Henderson-Hasselbalch)
11. What is the pKa of the unknown acid? _____________
12. This point in the titration is called the: the __________________ point
Please answer 
