Penny Lab Report Sample

Penny Lab Report Paper Research Question: What is the percent composition of Copper and Zinc in a positive penny? Aim: The purpose is to determine the percent composition of Zinc and Copper metals in a post-1983 penny with the use of HCI. Variables: Independent Variable: percent composition of Zinc. Dependent Variable: percent composition of Copper. Controlled Variable: Military of HCI, and year tot penny. Apparatus: Beaker Goggles penny Distilled Water Method: Note that HCI is an acid and must be cautious around this acid for it can burn your eyes so wear goggles, and wash hands after the lab. I. Retrieve a penny that is post 1983, and clean and dry the beaker you are going to use to make sure it has no residue from any previous users. 2. Fill 3 slots into a copper about 1/3 of the way or till you see the gray portion. (Note it will be more effective if each filling mark is at 1200 angle Of each Other. ) 3. Once the penny has been filed, weigh it and record its mass. 4. Weight the beaker and record its mass, then add penny in the beaker and mass or you can indirectly measure the mass by adding the penny mass with the beaker mass. 5. We will write a custom essay sample on Penny Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Penny Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Penny Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Place the penny in the beaker and add the HCI. Let sit for a day and recover your penny. 6. After the penny seems hollow retrieve the copper shell and mass it. 7, Once massed use the percent composition formula to find out how much copper is in a penny. (Percent composition formula: % comb= partial mystical mass x 100) 8, Subtract your finding of the percent composition of copper from 100 to find percent composition of zinc, 9. Repeat steps for multiple trials. Data: Date of penny: 1984 Mass of Beaker: 29. Gag Mass of penny: 2_gag Mass of beaker + penny: 32. 1 Mass of copper residue: Alga % comb Copper: 35% . Gag. gag x 100 = cue % comb. Zen-65% Pre Mass (g)l Post Mass (g) I % composition Cue % composition Zen 1 2. Gag o_gag | | 2. Gag 0. Gag 130% | 2. Gag 0. Gag | 2. Gag 0. Gag | | Average Mass of copper- Bag. Cue Conclusion: At the end of the experiment, through the use of percent composition, the copper within the post-1983 penny was found to be 35 percent, and 65 percent zinc. So me sources of error were filing the pennes sides to open it up for the reaction, The only solution to the problem is keep filing the. Human error was he largest source tot error in the lab. Finding the mass tot two objects and using indirect measurements could lead you to the wrong number depending on rounding, thus slightly increasing or decreasing your percent yield in the experiment. Also if you use the wrong sit figs while solving for the percent composition this could cause problems. If were to retry lab, would make sure to file more than what thought was needed, and to make sure to get a penny of the same year for a second trial. By adding a catalyst, a change in the speed of the reaction could reduce the time needed.

Will the World Starve essays

Will the World Starve essays Looking out a window upon a barren desert, a dry wasteland unfolds as a carpet to nowhere. Abandoned cities dot the horizon, as the ruins speak volumes to the once populated extravagance of a country which lived on wealth and opportunity. The vision just described is not one out of a Hollywood movie script, but one that is not only possible but probable. Currently, the world population numbers over six billion, with China alone cradling over one-sixth of the worlds total population. With the world population increasing at a rate of one hundred million a year, the numbers are expected to hit ten billion by the end of 2040. Most scientists agree that the maximum number of people that the earth can sustain is fifteen billion, leaving the earth in a quandary before the end of the twenty- first century when the total world population is expected to reach a staggering sixteen to eighteen billion. The consumption of the worlds natural resources due to this exponential growth could result in worldwide famine, a complete breakdown in the world market, uncontrollable outbreaks of disease, and widespread crime and disorder. Currently, the ratio of land which can be used for agricultural endeavors is estimated to be one in nine acres. The worlds produce producer is only a small sliver of a total land mass apple pie sliced into nine equal, yet tiny slices and as the amount of soil suitable for agriculture dwindles, the slice with which the world relies on continues to shrink. Considering the little amount of available farmland, it should be expected that there would be more of an effort to conserve this vital resource, but unfortunately the issue has not yet risen to a level of global importance. The amount of fertile topsoil is becoming more and more unusable for agriculture. Water, used for the irrigation of the worlds life giving crops, contains naturally dissolved miner...