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Problem 27
In which of these solutions will HNO2 ionize less than it does in pure water? a. 0.10 M NaCl b. 0.10 M KNO3 c. 0.10 M NaOH d. 0.10 M NaNO2
Problem 28
A formic acid solution has a pH of 3.25. Which of these substances will raise the pH of the solution upon addition? Explain your answer. a. HCl b. NaBr c. NaCHO2 d. KCl
Problem 29a
Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. a. a solution that is 0.25 M in NH3 and 0.18 M in NH4Cl
Problem 29b
Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. b solution that is 0.15 M in HCHO2 and 0.25 M in NaCHO2
Problem 31
Calculate the percent ionization of a 0.20 M benzoic acid solution in pure water and in a solution containing 0.25 M sodium benzoate. Why does the percent ionization differ significantly in the two solutions?
Problem 33a
Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. a. 0.15 M HF
Problem 33b
Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. b. 0.15 M NaF
Problem 33c
Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. c. a mixture that is 0.15 M in HF and 0.15 M in NaF
Problem 35
A buffer contains significant amounts of acetic acid and sodium acetate. Write equations showing how this buffer neutralizes added acid and added base.
Problem 36
A buffer contains significant amounts of ammonia and ammonium chloride. Write equations showing how this buffer neutralizes added acid and added base.
Problem 37
Use the Henderson–Hasselbalch equation to calculate the pH of each solution in Problem 29.
Problem 39
Use the Henderson–Hasselbalch equation to calculate the pH of each solution. c. a solution that contains 10.0 g of HC2H3O2 and 10.0 g of NaC2H3O2 in 150.0 mL of solution
Problem 41a
Calculate the pH of the solution that results from each mixture. a. 50.0 mL of 0.15 M HCHO2 with 75.0 mL of 0.13 M NaCHO2
Problem 41b
Calculate the pH of the solution that results from each mixture. b. 125.0 mL of 0.10 M NH3 with 250.0 mL of 0.10 M NH4Cl
Problem 43
Calculate the ratio of NaF to HF required to create a buffer with pH = 3.90.
Problem 44
Calculate the ratio of CH3NH2 to CH3NH3Cl concentration required to create a buffer with pH=10.34.
Problem 45
What mass of sodium benzoate should you add to 150.0 mL of a 0.15 M benzoic acid solution to obtain a buffer with a pH of 4.25? (Assume no volume change.)
Problem 48a
A 100.0-mL buffer solution is 0.175 M in HClO and 0.150 M in NaClO. a. What is the initial pH of this solution?
Problem 48b
A 100.0-mL buffer solution is 0.175 M in HClO and 0.150 M in NaClO. b. What is the pH after addition of 150.0 mg of HBr?
Problem 48c
A 100.0-mL buffer solution is 0.175 M in HClO and 0.150 M in NaClO. c. What is the pH after addition of 85.0 mg of NaOH?
Problem 52
For each solution, calculate the initial and final pH after adding 0.010 mol of NaOH. c. 250.0 mL of a buffer solution that is 0.255 M in CH3CH2NH2 and 0.235 M in CH3CH2NH3Cl
Problem 54
A 100.0-mL buffer solution is 0.100 M in NH3 and 0.125 M in NH4Br. What mass of HCl can this buffer neutralize before the pH falls below 9.00?
Problem 54d
Determine whether or not the mixing of each pair of solutions results in a buffer. d. 105.0 mL of 0.12 M CH3NH2 ; 110.0 mL of 0.15 M CH3NH3Cl
Problem 55b
Determine whether or not the mixing of each pair of solutions results in a buffer. b. 125.0 mL of 0.14 M HF; 195.0 mL of 0.070 M NaOH
Problem 55c
Determine whether or not the mixing of each pair of solutions results in a buffer. c. 55.0 mL of 0.15 M HF; 85.0 mL of 0.10 M NaF
Problem 56a
Determine whether or not the mixing of each pair of solutions results in a buffer. a. 155.0 mL of 0.15 M NH3 ; 175.0 mL of 0.17 M HCl
Problem 56b
Determine whether or not the mixing of each pair of solutions results in a buffer. b.155.0 mL of 0.15 M NH3 ; 155.0 mL of 0.10 M HCl
Problem 56c
Determine whether or not the mixing of each pair of solutions results in a buffer. c. 225.0 mL of 0.10 M NH3 ; 250.0 mL of 0.15 M NH4Cl
Problem 56d
Determine whether or not the mixing of each pair of solutions results in a buffer. d. 150.0 mL of 0.15 M HCl; 135.0 mL of 0.25 M NaOH
Problem 57a
Blood is buffered by carbonic acid and the bicarbonate ion. Normal blood plasma is 0.024 M in HCO3- and 0.0012 M H2CO3 (pKa1 for H2CO3 at body temperature is 6.1).
a. What is the pH of blood plasma?
