Determining Percent Composition of Unknown Copper Ore Sample
Iodine-thiosulfate Method: An Analytical Method
The objective of this experiment is to eliminate all interfering species from a sample of unknown copper ore in order to later determine pure copper content. Copper ore can be found in a mineral that contains pure copper and other species that is mined and can later have copper extracted from them (Taher, 1999). To eliminate all interfering species, such as Iron, Arsenic, and Antimony, from a sample of unknown copper ore one can use chemical reactions to eliminate interfering species by reduction and oxidation, and complex formation. Interfering species must be eliminated because they will react with reagent solutions, which ultimately will give untrue results. Iodine- thiosulfate method is used for this experiment, where iodine is the oxidant and thiosulfate is the reducing agent (Kos, 2015). Based on the averages of the percent composition of copper in copper ore being below 50% but above 0.4%, I hypothesize that the percent composition should fall within these two percentages. After completing this experiment, it was found that the unknown copper ore sample has an 11% ± 1%. This result falls within the hypothesized values …show more content…
For sample 1, 3.004 g of potassium iodide was dissolved in 25 mL of distilled water and added to sample solution. This resulted in a cloudy copper red solution and it was immediately titrated with the thiosulfate solution until it was a creamy coffee colour, no red colour remained. 5 mL of soluble starch solution and 1.013g of potassium thiocyanate was added. Solution was immediately titrated until end-point, which is a solution that no longer has any blue/purple colour and looks similar to a milky substance. Repeat process on second sample (see table 1 for volumes consumed during
Iodine-thiosulfate Method: An Analytical Method
The objective of this experiment is to eliminate all interfering species from a sample of unknown copper ore in order to later determine pure copper content. Copper ore can be found in a mineral that contains pure copper and other species that is mined and can later have copper extracted from them (Taher, 1999). To eliminate all interfering species, such as Iron, Arsenic, and Antimony, from a sample of unknown copper ore one can use chemical reactions to eliminate interfering species by reduction and oxidation, and complex formation. Interfering species must be eliminated because they will react with reagent solutions, which ultimately will give untrue results. Iodine- thiosulfate method is used for this experiment, where iodine is the oxidant and thiosulfate is the reducing agent (Kos, 2015). Based on the averages of the percent composition of copper in copper ore being below 50% but above 0.4%, I hypothesize that the percent composition should fall within these two percentages. After completing this experiment, it was found that the unknown copper ore sample has an 11% ± 1%. This result falls within the hypothesized values …show more content…
For sample 1, 3.004 g of potassium iodide was dissolved in 25 mL of distilled water and added to sample solution. This resulted in a cloudy copper red solution and it was immediately titrated with the thiosulfate solution until it was a creamy coffee colour, no red colour remained. 5 mL of soluble starch solution and 1.013g of potassium thiocyanate was added. Solution was immediately titrated until end-point, which is a solution that no longer has any blue/purple colour and looks similar to a milky substance. Repeat process on second sample (see table 1 for volumes consumed during