Question

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 K_a 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 :)

Answer 1

2.

1.