The pH of the solution containing 50 mL each of 0.10 M sodium acetate and 0.01 M acetic acid is [Given pKa of CH3COOH = 4.57]
- 5.57
- 3.57
- 4.57
- 2.57
Answer
(1) 5.57
Solution
The mixture is an acidic buffer. Both solutions have the same volume, so the ratio of concentrations equals the ratio of moles.
Henderson–Hasselbalch equation:
pH = pKa + [Salt][Acid]
= 4.57 + 0.100.01
= 4.57 + 1 = 5.57
Answer: (1)