9a. Phosphoric acid, H3PO4, is a trivalent acid with pKs1 = 2.12, pKs2 = 7.21, and pK $3 = 12.37. Calculate how many milliliters of 1.50 M HCI should be added to 300 mL of 0.400 M Na₂HPO4 to obtain a buffer solution with pH = 6.85. 9b. To the resulting buffer solution in question 9a, 16.0 mL of 0.500 M NaOH is added. Calculate the pH of the solution after this addition. 9c. When ammonium hydrogen phosphate, (NH4)2HPO4, dissolves in water, the following equilibrium is established: NH +HPO +NH3+H,PO K = 10-2.04 Based on the above equilibrium, calculate the concentrations of HPO and H₂PО in a 0.100 M solution of (NH4)2HPO4. 9d. Calculate the pH of the solution in question 9c. I

An analytical chemist is titrating 74.4 mL of a 0.3100 M solution of butanoic acid (HC,H,CO,) with a 0.3400 M solution of KOH, The p K_ of butanoic acid is 4.82. Calculate the pH of the acid solution after the chemist has added 72.3 mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added. Round your answer to 2 decimal places. do pH = 0 Pvacy Accessibilty Check 2021 McGraw-Hill Education All Rights Reserved Terms of Use Explanation V 11:16

A buffer solution is made that is 0.452 M in HC10 and 0.452 M in KC10. If K, for HC10 is 3.50 x 10-8, what is the pH of the buffer solution? pH : Write the net ionic equation for the reaction that occurs when 0.100 mol KOH is added to 1.00 L of the buffer solution. (Use the lowest possible coefficients. Omit states of matter.) +

4. A solution prepared to be initially 1 M in NH3 and 0.5 M in HCl is (Kb for NH3 = 1.8 x 10¯5):   (A) a solution with a pH less than 7 that is not a buffer solution  (B) a buffer solution with a pH between 4 and 7  (C) a buffer solution with a pH between 7 and 10  (D) a solution with a pH greater than 7 that is not a buffer solution  (E) a solution with a pH of 7