Question 1
What is the pH of a buffer system made by dissolving 10.70 grams of NH
4Cl and 20.00 mL of 12.0 M NH
3 in enough water to make 1.000 L of solution?
Kb = 1.8 × 10
-5 for NH
3.
◦ 9.34
◦ 9.18
◦ 9.26
◦ 11.03
Question 2
TRIS {(HOCH
2)
3CNH
2} is one of the most common buffers used in biochemistry. A solution is prepared by adding enough TRIS and 12 M HCl(
aq) to give 1.00 L of solution with [TRIS] = 0.30 M and [TRISH
+] = 0.60 M. What is the pH of this buffered system if the p
Kb is 5.92?
◦ 6.22
◦ 5.92
◦ 8.08
◦ 7.78