# Percentage uncertainty

Hello, I'm just wondering how ti calculate the percentage uncertainty of a 50cm3 burette with an uncertainty associated with the burette reading being 0.05cm3 and I did the titration 3 times so do I multiply by 3
Original post by Bird1234
Hello, I'm just wondering how ti calculate the percentage uncertainty of a 50cm3 burette with an uncertainty associated with the burette reading being 0.05cm3 and I did the titration 3 times so do I multiply by 3

No.

Each measurement has an associated uncertainty of ±0.05 cm3

To get the value for the titre you have to take two readings, so the uncertainty becomes ±0.1cm3

The percentage uncertainty is the 100 x (titre uncertainty)/(titre)

Each titration uncertainty is worked out in the same way, but different titres are not summative in terms of uncertainty.
Original post by charco
No.

Each measurement has an associated uncertainty of ±0.05 cm3

To get the value for the titre you have to take two readings, so the uncertainty becomes ±0.1cm3

The percentage uncertainty is the 100 x (titre uncertainty)/(titre)

Each titration uncertainty is worked out in the same way, but different titres are not summative in terms of uncertainty.

OK thank you very much 👍