1. Pick out a suitable acid/base pair to prepare a buffer with a pH of *(a) 4.5. (b) 8.1. *(c) 10.3. (d) 6.1. 2. A

1. Pick out a suitable acid/base pair to prepare a buffer with a pH of *(a) 4.5. (b) 8.1. *(c) 10.3. (d) 6.1. 2. A solution is prepared by adding 0.020 mole of sodium formate, NaCOOH, to 1L of 0.050 M formic acid, HCOOH. Assume that no volume change occurs. Calculate the H+ concentration. Ka = 1.6×10-4. 3. How many grams of sodium fluoride should be added to 612 mL solution of hydrofluoric acid (Ka = 6.8×10-4) to produce a buffer solution in which pH = 3.10? Ka for ascorbic acid, HC6H7O6, = 8.1×10-5. Calculate the H+ concentration and pH of 0.10 M ascorbic acid. 4. A certain hypothetical base MOH is 10% ionized in 0.005 M aqueous solution. is the Kb for this base? 5. mass of sodium glycolate should be added to 400.0 mL of 1.00 M glycolic acid to produce a buffer solution with a pH of 4.00? 6. Which has the greater buffer capacity: (a) a mixture containing 0.100 mol of NH3 and 0.200 mol of NH4Cl or (b) a mixture containing 0.0500 mol of NH3 and 0.100 mol of NH4Cl? 7. Consider solutions prepared by (a) dissolving 8.00 mmol of NaOAc in 200 mL of 0.100 M HOAc. (b) adding 100 mL of 0.0500 M NaOH to 100 mL of 0.175 M HOAc. (c) adding 40.0 mL of 0.1200 M HCl to 160.0 mL of 0.0420 M NaOAc. In what respects do these solutions resemble one another? How do they differ? 8. Pick out a suitable acid/base pair to prepare a buffer with a pH of *(a) 4.5. (b) 8.1. *(c) 10.3. (d) 6.1.