Titrations of NaOH and HCl

I have difficulty doing titration lab when I add NaOH to HCl with phenol indicator. I am assigned with an unknown molarity HCl solution. It worked perfectly when I practice with known molarities of NaOH and HCl (light pink was caught precisely). But when I tried with my unknown HCl, more than 10 times, I couldn’t catch the endpoint. It was clear then turned red immediately right after I added 1 more drop of NaOH. Does anyone know what to do with this problem?

@veronica
Depending on the drop size, sometimes your endpoint will be right in that gap! Sounds like you have tried to do it more slowly and you are still missing that exact moment, so I’d recommend either you just analyze your pH data and graph to find the exact point, or you try with another volume in the beaker to see if you can get closer to the exact point in the color change with a different volume.
If you still have questions, feel free to email support@beyondlabz.com

1 Like