Group 6 Presentation
Lab 6: Grand Central Equation
* Zinc Iodide can be gained through more than one method. We experienced making Zinc Iodide through zinc granules and iodine chips first and then we used Barium Iodide and Zinc Sulfate to make the zinc iodide. Chemists should prepare Zinc Iodide from its Elements rather than using double replacement reaction between Barium Iodide and Zinc Sulfate. In comparison to the grand central equation lab, the castle of quantification lab proves several benefits of using just Zinc and Iodine in formation of Zinc Iodide.
Zn + I2 ⟶ ZnI2 | BaI2·2H2O +ZnSO4·7H2O⟶ZnI2+BaSO4+9H2O |
Zinc used: (2g x $0.0625)=$0.125Iodine used:(3g x $0.1003)=$0.301Material cost for 3.1g of ZnI2 =$0.498Material cost for 10g of ZnI2 = $1.6 | 0.48g of Zinc Sulfate heptahydrate used= $0.01940.62g of Barium Iodide dehydrate used= $0.549Material cost for 0.48g of Zinc Iodide= $0.5684Material cost for 10g of ZnI2 = $11.84 |
% Yield from Zn and I2 reaction: 98.6%% Error: 1.39% | % Yield from BaI2·2H2O and ZnSO4·7H2O reaction:103.6%% Error: 3.6% |
The data above shows that Zinc Iodide formation through elements is much more efficient than using compounds. It costs less than half amount for Zn and I2 and the percent yield is also much closer to 100 when we use zinc granules and iodine crystals. Through the double replacement reaction, we gain a solid precipitate of Barium Sulfate at the end and the zinc iodide is the supernatant that we heated to get in solid form. It was not a completely pure method since the easier method is possible to form zinc iodide using only zinc and iodine. It was time consuming in terms of decanting the zinc iodide from barium sulfate solid. However, centrifuging made things easier and saved time usually spent in swirling. Keeping all these things in mind, we should prefer using elements for the formation of zinc iodide.
* What if we use all elements instead...