Hypothesis: If we add Zinc and Sodium Hydroxide to a penny, then the penny’s physical and chemical properties will modify.
Light brown, copper color; a little shiny
Treated with Zn + NaOH
Grey/silverfish with a copper coating around it
Treated with Zn+ NaOH & heated in the flame
Mostly gold with a little brown; extremely shiny
Discussion of Theory: In the Striking it Rich Lab we used our knowledge in class to manipulate the properties of different pennies. First, we had to mix Sodium Hydroxide (NaOH) in with water. In order for our lab to run more efficiently, we affected the rate of the dissolution of the NaOH by agitating the solution to increase the number of the collisions between particles. Next, after heating the pennies, we had to place Zinc into the beaker with the pennies. The Zinc created a process called dissociation, which is when ions break apart due to the dissolution of an ionic compound in water. The net ionic equation of Zinc and NaOH was found to be: Zn + OH= Zn(OH)2. The zinc Hydroxide changed the properties of the penny both physically and chemically. The Molality of the NaOH and H2O was found to be .5m. The Molality is determined by dividing the moles of the solute (NaOH) by the kilograms of solvent (H2O). The NaOH that was dissolved in the water was later heated and then mixed with Zinc. In this experiment, we dealt with Colligative properties which were changed throughout the penny. The penny was changed by the Zinc and Sodium Hydroxide, giving the penny a new physical appearance. After heat being applied in the final steps, the penny was changed into a gold color. The Colligative properties also depend on how much solute is in the solvent, so if we were to use more NaOH the gold color could have been increased even more. In this lab, the pennies formed alloys that resembled different forms of brass, shows us the pennies are made from zinc. A penny composed of copper and zinc didn’t react to form a precious metal, but to form an alloy, brass. Copper and Zinc were the two popular alloys used in this lab. The silver/grey penny that was treated with just the water and Sodium Hydroxide formed a less-combined alloy of copper and zinc, brass, than the gold coin that was treated with the Zinc, Sodium Hydroxide, and heat. These atoms of copper and zinc formed together in…