Zinc, Sodium, Beryllium, Copper And Boron

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Based on Physical and Chemical Properties, Determination of Identities of Zinc, Sodium, Beryllium, Copper and Boron
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,
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The density was calculated by measuring the mass and volume of one piece of the element and came out to be 0.12g/mL. The hardness of the element was 5.5 (the hardness of glass) based on the Mohs Hardness Scale. No magnetic attraction was observed when in contact with a magnet. The element was in an oil and the color of the element was a light gray. When the element was put in water, it dissolved immediately and bubbled. The beaker was warm to the touch. When reacting, the element dissolved into a sphere, ricocheted off the edges of the beaker, and sent off tiny sparks. When the element was added to the weak acid H2SO4, a similar reaction occurred. The element reacted immediately and bubbled. A gas was let out and the element completely dissolved, leaving the acid cloudy and opaque rather than clear. When the element was added to the weak base NaOH, it also reacted immediately and completely and let out bubbles and …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

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