25 mL of 0.10 M acetic acid is titrated with 0.10 M NaOH. What is the pH after 5 mL of NaOH have been added? Ka for acetic acid = 1.8 × 10–5.
So I created an ICE table in moles of each substance:
CH
3COOH + OH
- CH
3COO
-I: .0025 .0005
C: -.0005 -.0005 +.0005
E: .0020 0 .0005
Then I converted these back to M using n/V
E: .0667 0 .0167
After this, I used Henderson Hasselbalch equation of pH= pKa+ log[A
-]/[HA]
4.745+ -.602= 4.142
pH= 4.142
Should I be getting a negative number for my log[A
-]/[HA]?