Properties of Gases Essay

The purpose of this lab was to investigate and discover the physical and chemical properties of some gases. Throughout this lab the ability to identify if and when gasses were present was enhanced. During the first step of this lab, when obtaining the hydrogen from the mossy zinc and the hydrochloric acid, it took a lot longer than I thought it would for the water in the pipet to be displaced. I was tempted to remove the stopper and add another piece of zinc and see if that would make it go faster, but I did not want to interrupt the process. It seemed the longer that the mossy zinc was exposed to the hydrochloric acid the faster it dissolved and therefore more gas was produced. When the manganese and the hydrogen peroxide were exposed to each other there was much more fizzing produced than that of the zinc and the hydrochloric acid. I was surprised (although I don’t know why) that the lime water turned cloudy when exposed to breath. It is quite simple when you think about it that when you exhale you release carbon dioxide which as shown in the above data turns the lime water cloudy. Conclusion/Discussion During the course of this lab I learned a lot about the generation of gases. I was somewhat confused in the beginning about how to use some of the equipment for this lab. As the lab went on I figured it out and became much more comfortable with it. I thought some of the experiments were very informative and interesting. I especially liked the portions about reactions with a lit match or the glowing splint as it showed on a small scale if the gas produced was flammable or not. Questions A. Give two reasons why we fill the gas generator test tubes almost to the top with chemicals. 1. The first reason we fill the test tubes almost to the top with chemicals is so that the reaction between the two substances is high enough to the top to go through the rubber stopper and displace the water in the pipet and trap the gas. 2. The second reason is so that observations can be made easily about the reactions. If it was not almost completely filled we may have had to try to pick up the test tube or remove the tissue paper to make observations and this may have altered the results. B. What happens to the zinc in the hydrogen generation experiment? The zinc begins to slowly dissolve when exposed to the hydrochloric acid. The longer the zinc was submerged in the hydrochloric acid the faster it seemed to dissolve. C. What happens to the manganese in the oxygen generation experiment? The manganese produced large amounts of fizzing when exposed to the hydrogen peroxide. It was difficult to tell whether the manganese was actually dissolving or just fizzing. D. Write a balanced equation for the reaction between O2 and H2. 2H2 + O2 2H2O E. What is the function/purpose of the bromothymol blue in the CO2 experiment? The purpose of the bromothymol blue was to show the reaction of the chemicals and the gas that was formed. Since the bromothymol blue changed from blue to yellow, that signified that the gas formed was acidic. F. Bromothymol blue is blue in the presence of basic solutions, and yellow in the presence of acidic solutions. If your solution is a murky green, what might you assume about the solution? I would assume one of two things. There may have possibly been a contamination of the substance. The other possibility might be that the pH of the solution is neutral. If the bromothymol blue turns a murky green color this may indicate that the substance is neither basic or acidic.