Calculate the pH of the following buffer solutions: (a) a solution made by dissolving 3.198 g KH2PO4 (136.09 g/mol) and 2.833 g K2HPO4 (174.18 g/mol) in water to give 100. mL of solution. Stepwise acid dissociation constants for phosphoric acid may be found in your textbook. (b) a solution made by mixing 40.00 mL 0.21 M C5H5N with 10.00 mL 0.34 M C5H5NHCl. The base dissociation constant Kb is 1.50 x 10-9 for C5H5N. Assume that the final volume is the sum of the volunes of the two solutions that are mixed.
Calculate the pH of the following buffer solutions: (a) a solution made by dissolving 3.198 g...
Calculate the pH of the following buffer solutions: (a) a solution made by dissolving 4.550 g KH2PO4 and 1.871 g K2HPO4 in water to give 350. mL of solution. (b) a solution made by mixing 35.00 mL 0.35 M N2H4 with 15.00 mL 0.21 M N2H5Cl. The base dissociation constant Kb is 8.50 x 10-7 for N2H4 . Assume that the final volume is the sum of the volunes of the two solutions that are mixed.
PO, and of K2HPO, PM phosphate buffer for KH2PO4 and 1/4.10 YM 15. (LO 12) Calculate the mass of KH2PO4 and of ko required to prepare 100 mL of a 150 mm phospha at pH 7.2. The relevant acid dissociation is te H2PO4 = H+ + HPO2-nas and the pk, = 7.2. The formula weights are 136.09 g/mol for KH2PO4 and 174.18 g/mol for K2HPO4.
Use the Henderson-Hasselbalch equation to calculate the pH of each of the following solutions. A. a solution that contains 0.800% C5H5N by mass and 0.950% C5H5NHCl by mass (where pKa=5.23 for C5H5NHCl B. a solution that has 17.0 g g of HF and 27.0 g g of NaF in 125 mL m L of solution (where pKa=3.17 for HF acid)
What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M methylamine, CH3NH2, with 25.00 mL of 0.10 M methylammonium chloride, CH3NH3C1? Assume that the volume of the solutions are additive and that Kb = 3.70 times 10-4 for methylamine. 10.27 10.57 10.87 11.78 Which statement about buffers is true? Buffers have a pH = 7. Buffers consist of a strong acid and its conjugate base. A buffer does not change pH on addition of a...
6. What is the pH of a buffered system made by dissolving 17.42 g of KH2PO4 and 20.41 g of K2HPO4 in water to give a volume of 200.0 mL? The Ka2 for dihydrogen phosphate is 6.2 x 10-8 and the equilibrium reaction of interest is H2PO4 (4) + H20 <-> H30* ( HPO4 (4) 7. Determine the pH of a 0.188 M NH3 solution at 25°C. The Kh of NH3 is 1.76 x 10-5. 8. Calculate the pH of...
Calculate the pH of a solution made by adding 42 g of sodium acetate, NaCH3COO, to 22 g of acetic acid, CH3COOH, and dissolving in water to make 300. mL of solution. Hint given in feedback. The K, for CH3COOH is 1.8 x 10-5 M. As usual, report pH to 2 decimal places. Answer: Calculate the pH of a solution made by adding 59 g of sodium acetate, NaCH3COO, to 22 g of acetic acid, CH3COOH, and dissolving in water...
What is the pH of a buffer solution that is made by dissolving 16.6 g of KClO in 495 mL of 0.355 M HClO? (Assume the total volume is 495 mL).
A stock solution of analyte is made by dissolving 34.83 mg of copper (II) acetate hexahydrate (fw = 289.73 g/mol) in 25.000 mL of water. A second stock solution of internal standard is made by dissolving 28.43 mg of germanium (I) acetate (fw = 190.74 g/mol) into 25.000 mL of water. These solutions are used to make a series of standards for flame atomic absorption analysis calibration. The standard solutions (each 10.00 mL total volume) should have the following concentrations...
An aqueous solution is made by dissolving 11.24 g of sodium phosphate (tribasic) anhydrous salt in water to make 250 mL of solution. What is the expected pH of this solution? The pKa values for phosphoric acid are 2.15, 7.2, and 12.38.
What is the pH of a solution made by mixing 40.00 mL of 0.100 M HCl with 35.00 mL of 0.100 M KOH? Assume that the volumes of the solutions are additive. 1.64 10.00 12.36 13.36 2.17