Question

Hi,
This may sound like a dumb question but I am stuck.

I have worked out everything from a titration and I am now trying to work out my overall % purity.

It is 86.0% +/- 1.3%
What will 86.0% + 1.3% be and what will 86.0% - 1.3% be?

Answer 1

I assume this is absolute percent (meaning the number and not the sign); therefore, 86.0 + 1.3 = 87.3% and 86.0-1.3 = 84.7%

If these are not absolute percents, then
86.0+1.3%of 86.0 is
86.0 + (86.0*0.013) = 86.0+1.11 = 87.11%

Answer 2

My teacher got this for her results?
90.0% ± 1.27%

90.0% + 1.27% = 90.014
90.0% - 1.27% = 89.988
Her number I think she was getting the percentage from was 20.00 cm3
I am very confused?

Answer 3

I have struggled with this and I see no combination that will give the answers your teacher obtained. If you have some additional information I may be able to help. From your post I thought the 1.27% may be 1.27% of some number. That number would need to be 0.11 to give 0.014.

Answer 4

Ok, thank you very much for trying. It was to do with a whole load of calculations working out the titration and purity etc. I think I'll just leave it and ask my teacher.

Thank you again.

Paula