# Lab help

My group messed this experiment up and now i have to get a good grade(i receive 50% on all of my labs!). I would highly appreciate your input.
Our teacher gave us a procedure sheet, which we "accurate followed"
This is what we did:(If this is not enough i have a few more steps that were done before but i do not think they are important..)

Redox titration;Analysis of Hydrogen Peroxide

Take 125Ml Erlenmeyer flask, transfer 1.0ml of the commercial hydrogen peroxide. commercial??
Measure 5Ml of 6M sulfuric acid into a cylinder and than add it to the Erlenmeyer flask.
Open the buret stopcock and allow 5-8ml of potassium permanganate to flow into a flask.
Add as much as of KMn04 as needed to see a color change(turned pink) The burret was labeled in ml units.
We did those steps 3 times to the best results.
We also recorded a volume of KMNo4 used and averaged it. the result was 16.5

I am kinda confused what should i do in order to calculate the % error, number of moles of H2O2;KMn04 by using (C=N/V) C=n/v; C of MnO4 was given at 0.025M.
Here are the numbers that were given to us:
Concentration of KMnO4 =0.025M
Theoretical Moles of H2O2(8.88*10 to the power of negative)
%uncertainty of a burret is plus/minus 0.05ml. -My teacher gave us a formula:(0.05+0.05):avg volume of KMnO4*100 not sure what do i determine with this formula(% uncertainty of a solution??)

Here are the 1/2oxidation and 1/2 reduction equations(written on my paper by a teacher):
½ reduction: H2O2---> O2 + 2H+ + 2e
½ reduction: MnO4- + 8H+ + 5e = Mn2+ + 4H2O -Purple

Full balanced equation(done by me)
2MnO4 + 16H + 5H202--->5O2 + 10H + 2Mn2+ + 8H2O

I have calculated moles of H2O2

H2O2:0.025*0.0165ml(average volume of KMNo4used):5and the result *2=0.000165 moles

Now i have to find moles of MNo4; % uncertainty and % error.
So confused..

Thanks,
SOL