Question 1
Which of the following acids (listed with
Ka values) and their conjugate base would be the best choice to make a buffer with a pH of 2.34?
◦ HClO
2,
Ka = 1.1 × 10
-2◦ C
6H
5COOH,
Ka = 6.5 × 10
-5◦ HClO,
Ka = 2.9 × 10
-8◦ HCN,
Ka = 4.9 × 10
-10◦ HF,
Ka = 3.5 × 10
-4Question 2
A 1.0 L buffer solution is 0.250 mol L
-1 CH
3COOH and 0.050 mol L
-1 CH
3COOLi. Which of the following actions will exceed the capacity of the buffer?
◦ adding 0.050 moles of CH
3COOH
◦ adding 0.050 moles of HCl
◦ adding 0.050 moles of CH
3COOLi
◦ adding 0.050 moles of NaCl
◦ adding 0.050 moles of NH
4Cl