Chemistry HL Uncertainity

[dexter]

I take both Bio and Chem HL for bio labs you basically have to put the uncertainity of the appartus such as plus minus 0.01g, as for chemistry its a little bit more complecated, the thing is i know NOTHING , my friend was telling something called literature value and discrimant can some one tell me what is needed EXACTY please??

[ivy12003]

[quote name='dexter' post='30179' date='Dec 13 2008, 07:02 PM']I take both Bio and Chem HL for bio labs you basically have to put the uncertainity of the appartus such as plus minus 0.01g, as for chemistry its a little bit more complecated, the thing is i know NOTHING , my friend was telling something called literature value and discrimant can some one tell me what is needed EXACTY please??[/quote]

Not sure what discriminant is, but literature value is comparing what you actually got in your experiment to what you were expecting to get. i.e. If I was expecting something to be 1.01 V and I get 0.98 V, I can find my accuracy/percent yield by dividing my actual value over my theoretical value. 0.98/1.01 x 100% and get percent yield. There's an actual topic in the syllabus so you can double check what exactly you are expected to know.

[avrila]

I suggest you to refer to IB Study Guide: Chemistry For the IB Diploma, 2nd Edition.
It is the latest edition that provide new topic for uncertainty. It provides you with what you need to be put in the lab report.
If you are not sure of how the book looks like, you can take a look at this link:
[url="http://www.ib-source.com/title_info.php?id=303"]http://www.ib-source.com/title_info.php?id=303[/url]
Basically in chemistry, for the uncertainty, you need to find the 'percentage uncertainty' if the calculation involve 'x' or division.
You can refer the book for further explanation.