[WRX23]

Hello everyone! I'm currently doing an undergrad chemistry lab for acid-base titrations. I'm almost done, but struggling on finding errors that could be associated with the lab that are NOT human errors. My TA gave one example, saying to "consider the volume at the equivalence point". I'm not too sure what that means, does he just mean that since our measured volumes are not going to be the same as the actual values, and therefore messes with data? If someone could help me with that and possible identify any other non-human errors involved with this experiment I would greatly appreciate it.

Thank you so much.

[Corribus]

One of the biggest sources of error in any experiment is the fact that instruments are not perfect. Using a ruler, for example, there will always be an error in measuring the length of a six inches. Either the markings on a ruler may actually be in error (sacrificing accuracy) or the gradations/markings may be spaced too far apart to give you decent precision. If you are trying to measuring something that is 4.5 inches long, and your ruler only has gradations at every inch... well, you can see the source of error there, I'm sure. This could come down to human error, in a way, if the human isn't choosing the right measuring device for the task at hand. But this isn't what we usually think of as human error - which is generally operating error.

Given that, can you think of places in your experiment where there could be imperfections in the measuring devices themselves? For instance, what quality is the glassware you are using? How sensitive is your pH meter (if you used one)? When was the last time your instruments were calibrated? What is the purity of your chemicals? Etc.

[Borek]

Equivalence point and end point are two different things.

titrations.info has a good discussion of the titration errors.