61. Solving a chemistry problem

4. Take the uranium content in the ore from task No. 5 as the arithmetic mean of eight determinations. The standard deviation is 0.025%. Find the confidence limits of the result at a confidence level of 0.95 and determine if there is a systematic error in the analysis method used.
No. 5. The uranium ore was converted into uranium (IV) from a sample of the ore and titrated to 0.0100 N. potassium permanganate solution:
2MnO4- + 5U4+ +2H2O ↔ 2Mn2+ + 5UO22+ + 4H+
Calculate the percentage of uranium in the ore from the following potentiometric titration results:
VKMnO4, cm3 2.0 10.0 18.0 19.8 20.0 20.2 22.0
E, mV 301 303 359 389 1173 1486 1498
Plot titration curves in the coordinates E - V and ΔE/ΔV - ΔV. Write the Nernst equation for this reaction.