1.1. A student added 2.4 g of a sample of ethanedioic acid, H₂C₂O₄.nH₂O to water and made up the solution to 250 cm³. This solution was titrated against 25.0 cm³ of 0.1 mol dm^-3 KOH solution. The student's solution 

Use the results to calculate the amount, in moles, of ethanedioic acid in the standard solution. 

1.2. Using your answer to part a), calculate the following.

i) The M_r of the ethanedioic acid. 

[1] 

ii) The value of n in H₂C₂O₄.nH₂O.

[2] 

1.3. At the start of the rough titration, the student had not removed the funnel from the burette. The funnel was removed before the final rough titration reading was taken.

Explain what effect, if any, this will have on the final reading of the rough titration.

1.4. The burette used by the student for their titration has an error of ±0.05 cm³. It was used to determine the initial and final reading of the titration.

Calculate the maximum percentage uncertainty in using the burette, using an average titre of 18.70 cm³. Note, this is not the answer for part a). Give your answer to 2 decimal places.