Notes

Through specific tests, we observed that unknown compound #5, was found to have an aromatic group and a carboxylic acid group and unknown #19 was found to have a carboxylic acid group, hydroxyl group and a phenol group.

Through spectroscopy data, we were correct in that the unknown compounds had the functional groups that we tested in part a.

Overall, we synthesised camphor through the oxidation of 0.0013 mol of borneol using a sodium hypochlorite solution in acetic acid as an oxidising agent and confirmed it by comparing its melting point with the authentic camphor. When adding the 4.75 mL of bleach the flask went from a cloudy solution to a clear solution with a precipitate on top, the synthesised camphor. The melting point of the synthesised camphor and authentic camphor were relatively similar but the percentage yield indicated that there was too much synthesised camphor obtained (due to it not being dried).

Conclusion: Berri orange juice (2000 μL aliquots, in triplicate) was titrated against a 0.104 M solution of N-bromosuccinimide. The concentration of Vitamin C in the fruit juice was determined to be 55.0 mg/L.

Overall, we synthesised an iron oxalate complex through the reaction of potassium oxalate and iron(III) chloride. Iron oxalate (1000μL aliquots) was titrated against a 0.200 M potassium permanganate solution. The average %m(Oxalate) in the complex was found to be 35.14%.

First, we weigh 0.26g of iron(III) chloride into a small beaker and 1g of potassium oxalate monohydrate. We then add 1.5mL if distilled water and place it onto a hot plate until dissolved. After, we mix the hot potassium oxalate and iron(III) chloride solution and add it to an ice bath (with 5mL of distilled water) for 10-15 mins. Then, we add the solution to a vacuum filtration to collect the precipitate. Lastly, we measure the mass of the product.

Once part A is completed, we gather the iron oxalate complex (0.25 g complex in 25 mL of deionised water). We setup the titration and rinse the burette with KMnO4 solution. Once rinsed, half-fill the burette with the KMnO4 solution. In three seperate conical flasks add 2 mL of the iron oxalate solution and 5 mL of 2 M H2SO. Then place one conical flask onto a hotplate for around 20-40 seconds and titrate it with the permanganate solution until there is a faint pink colour that stays for at least 30 seconds. Once you gather three concordant results you calculate the percentage of oxalate in each sample.

During part A, the synthesis of the iron oxalate complex, once we mixed the iron(III) chloride solution and potassium oxalate solution together, it immediate changed to green colour once we stirred the flask. The precipitate obtained after the vacuum filtration was a shiny powdery crystal substance.

During part B, i.e titration (where we aimed to determine the concentration of oxalic acid), it took a while to get a faint pink solution. The titre of each of our results are: 3.4 mL, 3.5 mL, 2.9 mL and 3.4 mL. Finally, get an average %m(Oxalate) in the complex (based on concordant results): 35.14%.