Lab Report Example. Solid Copper

Introduction:

The purpose of this lab was to conduct a series of reactions that take the solid form of copper (Cu), and conduct a series of reactions until it once again becomes solid copper. The primary goal of this experiment was to maintain the same mass of solid copper throughout the reactions. During the lab, the law of mass conservation was used. The law of mass conservation dictates that mass can neither be created nor destroyed; regarding this experiment, this was utilized in the aspect that the mass of the copper was not changed through either physical or chemical means. Through a single displacement, the reactions yielded a precipitate, meaning a solid formed in a chemical reaction. This took place during a single displacement reaction of a copper ion, which was replaced, forming the solid copper. 

Procedure:

The materials used in this lab were 0.60 grams (g) of Copper (Cu) wire, 10 mL Hydrochloric Acid (HCl), 10 mL of Nitric Acid (HNO3), 18 drops of Sodium Hydroxide (NaOH), 10 mL of Sulfuric Acid (H2SO4), 0.06 grams (g) of Zinc wire (Zn), a Buchner funnel, four 50 oz beakers, one 100 oz beaker, as well as a heat source. To begin the experiment, the copper wire was cut using wire cutters into small pieces and then placed into the 100 oz beaker. Once placed in the beaker, 10 milliliters (mL) of Nitric Acid (HNO3) was added to the beaker that contained the pieces of copper wire. Once placed under a fume hood while resting on a hot plate, the copper wire was dissolved, which also produced Nitrogen Dioxide gas (NO2). Once removed from the fume hood and allowed to cool, Sodium Hydroxide (NaOH) was slowly added into the beaker while being stirred until it became a chunky green mixture. Once the mixture was formed,  approximately 10 mL of Sulfuric Acid (H2SO4) was slowly stirred into the previously formed mixture. This resulted in a transparent blue aqueous solution. The 0.60 grams of Zinc wire, cut into small pieces, was then added to the solution until it had become cloudy. To complete the experiment, Hydrochloric Acid (HCl) was added into the mixture, causing the liquid to become transparent, and the solid matter to return to copper. Once the solid copper was filtered out of the solution and the remaining liquid was disposed of, the copper was allowed to dry and was then measured. 

Discussion: 

The purpose of this lab was to conduct a series of experiments to represent the copper cycle, beginning with copper in a solid state, and then bring it back to a solid state through the series of reactions. To fulfill the goal of the experiment, the copper wire was measured and recorded, totaling out to be 0.06 grams. In order to meet the objective of the lab, the amount of copper that resulted from the final reaction ideally would have been equivalent to the initial mass of copper. This would display the accuracy of the results, as well as follow the law of mass conservation.

It was very important to make sure that all of the measurements of the reactants and products were accurate from the scale as well as the graduated cylinders and beakers. The recorded data of both the initial and final mass of copper were then plugged into the formula: final copper mass/ initial copper mass x 100, in order to determine the percent of copper remaining. This calculation allowed the amount of copper that was initially started with to be compared to what was left to insure that the reaction was done properly. If the reaction was done properly, it would show that the same amount of copper that was initially reacted with had the same mass of the copper that was yielded by the final experiment. 

The results from the experiment detailed that the amount of copper used in the experiment was the same exact mass as the initial copper. With each experiment done during the lab, all had distinct characteristics that allowed for observations to be made. These observations were made by noting the result of gas, liquid, or solid formations during the reactions that took place. It was important to take smell, visual appearance, and texture into account while making the observations. Each observation allowed for the confirmation that the experiment was heading in the right direction. The final reaction yielded pieces of solid copper (Cu), which showed the final reaction had taken place successfully. 

Though the lab was successful in maintaining the original mass of the solid copper, there were minor errors detected. The first error detected was the contamination of the copper wire while cutting it with the wire cutters. While cutting, if not done correctly at the right angle, pieces of the cut copper flew to either the floor or the table This resulted in the contamination of the copper. Though it was not fully soiled and all pieces were recovered, dropping these shards onto an unclean surface caused the copper to lose its original purity. The second error noted was the speed in which the aqueous solutions were poured. When poured too fast or too slow, the reactant mixing had an effect on the solution. The dilution of the mixture was especially affected when poured at an unsteady rate. This caused a slower and unstable reaction time, leading to the first step of the cycle to have to be repeated during the experiment. This affected the credibility and crucial timing of the experiment. In the future, the first error of the experiment could be avoided by making sure there is a guard up around the beaker where the copper wire is to be dropped into. This would result in a lower likelihood of any copper being misplaced or dropped. The second error could be avoided by ensuring that the rate of which the reactants are being combined enter at a continuous and steady rate. This will allow for the proper reaction to take place as well as the experiment to yield more favorable results. 

In a final analysis, the measurements that were needed to make this lab a success were finished and proved to be correct. The reactions were all done carefully, and resulted in the correct results taking place. The calculations yielded that the initial copper mass and the final copper mass were equivalent. These results did match the initial predictions made for the lab because when the final mass of the copper (Cu) was taken, again, it showed that it was the same mass as the initial copper (Cu).