Chemistry lab reports

[Sauliooz]

So it is almost a deadline when i have to hand in all my lab reports and i wanted to improve them a bit..

i downloaded a few usefull noted about lab reports, but i couln't find any information about inaccuracies and how important it is to include them..
i mean i did include the possibility of inaccuracies during the measurement, but as i know there is also a possibility to convert them into percentage inaccuracies and then use it during calculations.. this should lead to calculation inaccuracy or something like that..
however, during some experiments there is a lot of calculation, so does this mean that I still have to go through each substitution and multiplication using some inaccuracy, add them, etc. and then create an overall calculation inaccuracy???

btw I'm SL and I've recently heard that it is a must just for Chem HL.. is it true??

any other suggestions.. for example does creating some colourful table instead of a simple table add any points?

[Ongfufu]

i believe you have to add all the uncertainties with a ± sign for all calculations, or state clearly errors u have made in a separate paragraph. and colourful tables wouldn`t help a bit.

[Sauliooz]

yeah, stuff like that:
V(NaOH) = 25 cm3 ±1
C(NaOH) = 1.0 mol dm-3
V(H2O) = 25 cm3 ±1
V(Hydrolyzed solution) = 25 cm3 ±1

but what about converting them into percentage inaccuracies, like for V(NaOH) it should be
(1/25)*100%

and when i make some calculations, like multiplying one value with some inaccuracies with another value i know that there is a method when you add the percentage inaccuracies... the results of added percentage inaccuracies but be an inaccuracy for your calculation result..
thats hard to explain

for example:
i have that after the experiment 1 i 25 cm3 ±1 NaOH to react completely with HCl.. after the experiment 2 i needed 26 cm3 ±1.. after experiment 3 i needed 27 cm3 ±1.. and now i want to calculate an average... so my average is (25+26+27)/3... and it is logical that its inaccuracy should be larger than ±1.. so should i be trying to find it?


or is it all optional or HL stuff???

[Bandev]

It is HL only, really if you want you can do it properly, as you are trying to work out how to do, but reallly you only need to do really simple ones, have a look at my prac report Absolute Zero which is in the example section of this sub forum as for what is requested for uncertanties for SL. If you want to see the HL requirement look at my Reaction orders prac.

Edited March 19, 2008 by Bandev