During the lab, “Develop an Activity Series,” numerous metals were put into different aqueous solutions to see how these metals would react with each aqueous solution. The main objective of the experiment was for the students to develop an “activity series” that reflected the observations of each metal/solution reaction. After comparing the observations made about the reactions and putting them all in order from most to least reactive, an activity series was finally able to be made, which then reflected the outcome of the experiment. In this lab activity, four main solutions including aluminum nitrate, zinc nitrate, magnesium nitrate, and copper(II) nitrate) had to be placed into four separate wells in a tray. This was done by using a pipette. After this, a small sample of metals including zinc, aluminum, copper, and magnesium was also placed in one well of each of the solutions listed above.
The reactions that occurred were then observed and recorded, and used to develop the activity series.Even though there was no direct hypothesis for the lab itself, it was assumed that the final activity series developed would reflect the activity series given in the chemistry textbook within Figure 13. However this did not happen, the orders of the two activity series ended up being different.
From the textbooks example, the metals from the lab had been arranged from most to least reactive as Mg, Al, Zn, Cu. The activity series from the lab resulted in the metals being ordered from Zn, Mg, Cu, Al. Out of all of the metals Zinc was first due to the fact it reacted with three solutions, these reactions were shown through gas release, tarnishing, and color change. Next was Magnesium. Magnesium placed second due to its reaction with one of the substances and also showed apparent color change.
Copper which was third, seemed to react with the copper(III) nitrate, then also tarnished. Due to those two observations the Copper was labeled before aluminum. The aluminum did not react with any of the solutions. After review however, discovered was that the reaction was not the possible anyway. Copper had been decided to be left as the third most reactive even though copper and aluminum did not show any signs of being more reactive than one another. The differences in results from the reactivity series developed and the textbook version of the activity series could have been due to errors that took place during the lab experiment. First off, one of the substances used had been put into multiple wells even though it only belonged in one.
Cleanup action was taken to correct the mistake, but still could have possibly affected the lab results. Second, there had been many errors in the observations made, where people observed something that had looked like a chemical reaction so it was taken note of, although it could have not been a reaction at all. Lastly, there was a possibility that the metals could have entirely been mixed up and misplaced, This could be the reason why the metal Zinc was put as the most reactive, but the metal actually being observed could have been copper, aluminum, or magnesium. To reduce error in a secondary trial of this activity series lab, wells could be separated entirely to insure that solutions are not mixed. Also running multiple trials for extensive observations and being very observant of labels on the metals could help insure and or obtain results that are more accurate.