Question

What is the pH of a buffer solution that contains 0.350M pyruvic acid and 0.150M sodium pyruvate? Ka = 4.1x10^-3

Select one:

A. 4.72

B. 2.82

C. 2.02

D. 2.76

What is the pH of a 100.0mL buffer solution that contains 0.215M acetic acid and 0.255M sodium acetate after 0.055 mmol HCl is added. Assume no volume change. Ka = 1.8x10^-5.

Select one:

A. 4.61

B. 4.87

C. 5.03

D. 5.48

Calculate the change in pH after 0.010 mole HCl is added of 1L of pure water at 25 degrees Celsius? Assume no volume change.

Select one:

A. 7

B. 2

C. 5

D. 9

Calculate the change in pH of a buffer solution that originally contains 0.0500M ammonia and 0.0500M ammonium after 0.020 moles of NaOH is added to 1.0L. Assume no volume change. Kb = 1.8x10^-5 for ammonia. Hint you need pKa.

Select one:

A. 0.63

B. 0.18

C. 0.55

D. 0.37

Answer 1

After addition of 0.020 moles of NaOH 0.020 moles of ammonium will react with 0.020 moles of Nach & will form 0.020 mole a base a so then conc. of base = (0.0500 +0.020) m = 0.070 M comes of salt = (0.0500 -0.020) M 30.030 . Nocon port = pkb + log Sality = 4.74+ lorg (0030 = 4:37 pH = (14 – 4.37) = 9.63 : pH of the solution changes = (9.63 – 9:26). = 0:37: © oa - So, option () 0137 is correct.