By: Shreya Uppala, Lizzy Jolly, and Kyrie Harrell
Results:
The first element we tested was zinc. Since zinc was already known, the density was stated to be 7.13g/mL and the hardness was a 2.5 based on the Mohs Hardness Scale. No magnetic attraction was observed when in contact with a magnet. Zinc had a shiny appearance with a light gray color and the strips of zinc added to solution were approximately 5 cm. When zinc was tested with water there were no noticeable characteristics of a reaction occurring, such as bubbling or a color change. When zinc was added to the weak acid H2SO4, at first there was no noticeable reaction, however, …show more content…
The density was calculated to be 1.00 g/mL and the hardness was determined to be 3 on the Mohs Hardness Scale. The unknown did not seem to be attracted to the magnet when in close proximity. The element was dark gray in color and came in small pieces. When in water, the element showed no indication of a reaction occurring. When placed in H2SO4, the element bubbled and sank to the bottom. Occasionally the element rose to the top and then bounced back to the bottom of the beaker. The element changed color from dark gray to silver and reacted for a long time. When placed in NaOH, the element showed no indication of a reaction …show more content…
Zinc was used as a known based on the abundance of the element. Also, zinc acts as an example for how to observe acid and base reactions. When at first submerging zinc in the H2SO4 it seemed as if the zinc was nonreactive; however, after some time bubbles started to form a layer on the zinc indicating that a chemical reaction was occurring. The long wait time associated with an observable reaction can be seen as a limitation of zinc. If the reaction was not left to sit then it might be recorded that there was no reaction, as was done in our observations when zinc was submerged in NaOH. The density of zinc was also given as a way to practice accurate mass and volume measurements in order to calculate the correct density for both zinc and the unknowns. However, even with this practice with a known density, our density calculations were far off from the densities of the identified elements. This could have been due to using a graduated cylinder to measure volume because it causes variability when determining decimal places. Even without a correct density, we determined the Group 1 element, labeled A2, to be sodium based on its high reactivity in water and its appearance. We determined the Group 2