#titration

So here’s the thing. I was running a standard titration of a weak base with a strong acid to practice pH calculation, but when I added the phenol red indicator, it stayed a pale yellow instead of turning the expected light pink at the endpoint. I double‑checked the glassware, rinsed the burette, even switched the pipette, nothing changed. The only thing I changed was using a new batch of the indicator that I just received, and that seems to be the culprit. It feels like a simple dilution problem, yet the concentration was spot on, the acid was 1 M, and the base 0.5 M. Every time I pipet, the color never shifts—just a ghost of the original hue. Anyone else have a story about a batch of indicator going rogue? Also, is there a cheap test to confirm the indicator’s integrity before adding it to the mix, or am I doomed to repeat the titration until the dye actually responds? A quick anecdote: my friend tried to add a pinch of food coloring instead, and we all laughed, but that didn't solve anything either. Looking forward to any troubleshooting tips or theories; I’m tired of the colorless drama. Thanks.

I titrated 25 mL of 0.05 M acetic acid with a 0.1 M NaOH solution, using phenolphthalein as the indicator. The color change was not a sharp transition; instead, it faded gradually over several milliliters of base. The endpoint appeared later than the expected equivalence point, and the pink hue was faint at first, becoming more pronounced only after a significant volume of NaOH had been added. I suspect either the indicator concentration is too low, or there is a buffering effect from a secondary species. What could cause such a gradual transition? Should I adjust the indicator concentration, or is there a fundamental reason tied to the acid's pKa and the indicator's transition range? Also, could the solution's temperature or the presence of dissolved CO₂ be influencing the result? Any insights would be appreciated.

I tried to keep the solution well mixed and used a clean burette, but the problem persisted. I'm not sure if the issue lies with the titrant concentration, the indicator, or the experimental setup. Any guidance on troubleshooting this would help a lot.