Determining a substance by tritration Essay Example for Free

Determining a substance by tritration Essay Aim: Using the procedures of a standard acid base titration lab, the goal of this experiment is identifying the amount of Calcium Carbonate (CaCO3) that is presented in a calcium carbonate substance presented by our teacher. Hypothesis: Due to any unknown substance that we encounter in the chemistry room, we must take serious precaution, as the substance may very well be highly contagious and dangerous to smell, touch or taste directly. The only ability that we posses that can be used to observer this substance is our vision that is going to help us in determining the concentration of the substance. Although that with vision only, it will not suffice the need that is necessary to make that judgment as we need quantitative data (finding the exact concentration of calcium carbonate). Unless we have prior knowledge about this substance, the processes of a titration must be used. My hypothesis begins that this has about 60% concentration. Variables: Independent Variable: There is none in this experiment. The goal of this lab is not to include any variables that will change the concentration of the calcium carbonate. We need constant results for the concentration of the calcium carbonate, as that will determine the actual concentration of the calcium carbonate in our substance. Dependent Variable: The volume needed to titrate the calcium carbonate solution by using the phenolphthalein indicator. Though it is a clear substance, the indicator will change its color into pink when the solution becomes a base from an acid. By determining the amount of hydrochloric acid is needed to change the color of the solution, we can determine the concentration of calcium carbonate through some calculations. Controlled Variables: 1. The Distilled Water: The distilled water will be the only water that will be used during the entire experiment. The distilled water was prepared and resented by our teacher. 2. The calcium carbonate substance: The calcium carbonate substance was constant throughout the entire experiment. 3. The Hydrochloric Acid: The hydrochloric acid was one of the main components of this experiment. Therefore this acid was also prepared and presented by the teacher. 4. All Equipment: All the same equipments such as the pipette and the filter paper were used throughout the experiment. Apparatus: * Unknown white powdered substance * 50cm3 burette * 3 250cm3 Erlenmeyer flask * 200cm3 for hydrochloric acid * 0.1M of Sodium Hydroxide * Burette clamp * Retort stand * Distilled water * Goggles * Filter paper * A funnel * Phenolphthalein indicator * A scale * Paper towel * A spoon * Pipette * Pipette sucker * White paper Method: 1. First set up the retort stand and the retort clamp as indicated by the diagram below. Of course, the flask must be prepared in the subsequent steps. However unlike the diagram, place a white piece of paper beneath the flask so that the color change becomes more easily visible. 2. After placing the paper towel and scaling the scale, measure out approximately 10.0 grams of the unknown substance and record the exact mass 3. Add 200cm3 of 1.00-mol dm-3 hydrochloric acid and stir until the reaction is complete. 4. Filter the solution and withdraw 10cm3 using a pipette and make up to 100 cm3 in a volumetric flask. 5. Titrate 10cm3 portions against a standard 0.1M NaOH using the phenolphthalein indicator. 6. Record both quantitative and qualitative data. 7. Repeat the process of titration three times. Observation (Data Collection): Measurements: * Mass of Calcium Carbonate solution: * Burette: Calcium Carbonate solution made using 250cm3volumetric flask with an uncertainty of ?0.5cm3 * Pipette: 25.0cm3 of 0.100moldm-3 NaOH(aq) ?0.04cm3 Chemical Equations: Before we delve into the calculations, it is best that we list the necessary chemical equations of this lab. One must note that in this experiment, that there were two chemical reactions. Firstly, the first experiment occurs when the white substance mixed with the HCl. The second chemical reaction took place when the HCl solution meets with the .1M of NaOH 1. 2. Qualitative Data: Description of the substance used and produced Hydrochloric Acid Clear, viscous, Calcium Carbonate White, powder form Phenolphthalein Indicator Clear solution, comes in a bottle, add as drops Solution Produced in the end Bubbly, white liquid, most of the unknown mixture dissolved Clear/pink throughout. Quantitative Data: Measurement Recorded During the Experiment Trial 1 2 3 4* Initial Burette Reading (ml?0.05cm3) 0.00 0.00 0.00 0.00 Final Burette Reading (ml?0.05cm3) 5.45 5.90 5.60 5.40 *To note, for the calculations below, the supervisor at the time suggested the best data to use would be the average of the HCl used because the numbers found were very consistent. Calculations The following steps were taken so to find the % by mass of CaCO3 in the mixture 1. The moles of acid presented in 200cm3of 1.00 mol dm-3hydrochloric acid. 2. The moles of acid presented in 10cm3of the acid solution titrated. 0.00056molof HCl 3. Multiply the volume present in the volumetric flask. 4. The total moles acids remaining after the reaction with CaCO3 5. Subtract the value in 4 from that obtained in 1 to find moles acid used. 6. The stochiometric equation for the reaction of HCl and CaCO3 Hydrochloric acid+Calcium carbonateCalcium chloride+water+Carbon dioxide -Therefore the molar ratio is 1 mole of calcium carbonate to 2 moles of hydrochloric acid 7. Using this and the value in 5 to calculate the moles of CaCO3 present. Then calculate the mass of CaCO3 8. Using the value found in step 7 and the original mass of the mixture, here is the calculation to find percent of the mixture is made up of CaCO3 Uncertainties: * * * * Total Uncertainty= Conclusion: This experiment in general was very interesting. During this lab, I was able to learn of how we can identify the amount of a substance by knowing the concentration and volume of another. We were able to do so as we knew the moles and concentration of sodium hydroxide that had enabled us to find the unknown concentration of calcium carbonate. Because the actual percentage of CaCO3 was not given, we must concur that the accuracy of this lab has been affected and therefore must be assessed by our uncertainty percentage. The percent of uncertainties represents the desultory errors that may have occurred, which either may make the measurements bigger or smaller than the accepted value, due to imprecise measurement. One way to avoid future random errors, better equipment may be needed, or repetition of the measurements. Despite the uncertainties based on lab equipments and other mediums of measurements, one of the biggest possible sources of error lies in the systematic errors of this lab, especially finding the exact endpoint. Though the pink color should indicate when the endpoint is reached, in trial 2 and 3, the solution turned a faint pink color and my partners and I did not know whether that faint pink indicated the endpoint. This could have resulted in a measurement lower than the actual value. To possibly improve this source of error, I believe more time and trials should be allotted to the students. When I was doing my experiment, we were only given a single class time to follow the procedures, write down our notes, and clean up our experiment. If more time was allotted, then higher quality recordings could be made. This would then give us a clearer idea when the endpoint actually is. Next, though it is unlikely, to improve this lab we may have to rinse the burettes and other flasks prior to performing this lab. In my chemistry classroom, burettes and flasks are arranged so that the clean ones are clearly seen and labeled while the used ones are in the sink. However it could be possible that another student may have placed an unclean burette in the cabinet full of clean equipments. Therefore, for accuracy purposes, all equipment should be washed using soap and tissues. Reviewing and understanding the errors can significantly improve this experiment. Though my hypothesis of the concentration being 60% calcium carbonate was wrong, this experiment taught me the value and usefulness of the process of titration.

Religion :: essays research papers

Genetic Engineering Genes, or chromosomes, are often referred to as "blueprints" which are passed down from generation to generation. From the study of these hereditary materials, scientists have ventured into the recent, and rather controversial, field of genetic engineering. It is described as the "artificial modification of the genetic code of a living organism", and involves the "manipulation and alteration of inborn characteristics" by humans. Like many other issues, genetic engineering has sparked a heated debate. Some people believe that it has the potential to become the new "miracle tool" of medicine. "Advances in the field of genetic engineering could mean progress on an unprecedented scale for all civilization" - Gail Dutton To others, this new technology borders on the realm of immorality, and is an omen of the danger to come. They are firmly convinced that this human intervention into nature is unethical, and will bring about the destruction of mankind. "†¦ the promise of genetic engineering as a tool of medicine is matched only by the threat it would pose to human society and civilization." - Ann E. Weiss Rapid advances in medical science have fuelled the question of bioethics. However, as science takes leaps and bounds towards its goals, ethics are often just learning how to crawl. In fact, it has even suffered major backslides in some cases. Genetic engineering "raises serious ethical questions about the right of human beings to alter life on the planet". Changing the basic physical traits of an organism can lead to an unprecedented threat to life on the planet". With such dire consequences, where do we draw the line? What View Does Science Have on Genetic Engineering? For the first time in history, evolution has taken a backseat to the meddling of humankind with their own genetic makeup. There is an "ongoing realization that humanity is capable of directly shaping its own and other species’ evolution". As we ease into the twenty-first century, we realize that genetic engineering is undoubtedly going to have a dramatic effect on our lives. It seems that "with genetic engineering, science has moved from exploring the natural world and its mechanisms to redesigning it." Now, we must ask ourselves this, will that influence be for better, or for worse? However, even the responses of science differ in this topic. Scientists remain divided in their opinions. Some have warned against the hazards of genetic engineering, while others have dismissed these perils as inconsequential. Two opposing viewpoints, which is right?

Modern Family Essay

The show â€Å"Modern Family† is one of the most successful sitcom on television today. The show depicts a total of three families, a parental family, (Jay and Gloria) and the families of the two grown siblings, (Mitchell & Claire). Claire is married to Phil and has three children of their own, while Mitchell is a gay father with a live-in husband, Cameron. The on-screen worldview of the families are very open with an almost anything goes attitude that is based on an atheist or an agnostics perspective. The limited amount of shows that I watched did not display any references to God. The family values portrayed the â€Å"New Normal†, that is currently being offered on many new television shows. On the show, I witnessed a lot of light-hearted moments that made fun of the life choices that each character made, and how different characters resolved them. The comedy is situational, and dilemmas faced are often real-life, but offer whimsical, light-hearted solutions. The shows worldview is secular, but adheres to defining the â€Å"New Normal† in its application. The three families all interact with each other and depict three different types of households, all coping with everyday problems that define that particular group. When dealing with gay issues, Mitchel and Cameron are in the fore front offering an exaggerated look and perspective. Family issues are addressed by Phil and Claire, and how they interact with parenting of their three children. Jay and Gloria deal with life from viewpoint of an aging father, who marries a younger woman, who is currently pregnant with his child. The shows core values are loosely interwoven with standards and practices that suggest an anything is â€Å"OK† attitude, which would be expressed by secular humanist. Observations of this show are based on my own personal up-bring and how we handled different situations in our lives. My Christian parents would not have been so excepting of two men living together. Our family believed that marriage is between a man and a woman. â€Å"‘Do not have sexual relations with a man as one does with a woman; that is detestable†, (Leviticus 18: 22, NIV). Our family values were centered on our Catholic faith, whereas we believed and trusted in the Lord. In the show, Phil (husband of Claire) is portrayed as being a weak father figure, who is often laughed at and scorned by his family. He constantly wants to be everyone’s friend and does not fall into the role of a strong and guiding force within his family. In contrast, my father was the head of our household, and for a long time he was the sole provider. Both church and prayer were a large part of our daily lives. These are beliefs and traditions that I have passed onto my family. My views are in direct contrast to this sitcom. Its impact on my family is very little since I am not a regular viewer and the show is a negative influence on my personal worldview. I believe that the influence of this show on the American public is limited in scope. Many people watch and except the shows premise for what it is, just a funny comedy that really has no real value or worth. Other people will see it as an example of how a modern family should behave and create those same dynamics in their household. I see this show as a negative influence when it comes to the family. Television has a way of shaping public opinion. If enough similar programing is available, we as a society tend to accept the â€Å"New Normal† without question. In conclusion, the show â€Å"Modern Family,† is a portrayal of the American family that presents an atheist view on life. I saw no reference to God or even a slight suggestion that the family has a religious background. In today’s society the family is always being redefined by the media and has no religious insight. Television networks record on social and moral issues is very poor. The television executives believe the theory that they are open and honest, and present a product that the public wants. Modern Family is one networks’ answer to what is considered the â€Å"New Normal†, in today society.

The Civil Right Movement History - 1705 Words

The Civil Right Movement History can be absurd and sometimes can illustrate great accomplishment by great people. Why history is so important and significant to today’s society? It is something that people require to know about the pass and not remaking those same type of mistake again. Hence, history helps the world to understand changes and how the past causes the present to be the way it is in today’s society. Though the United States became a country with a rich foundation and great accomplishment that is well recognized around the world, but there is the dark and heartless side of it. For Instance, the Civil Rights Movement Is one of the good example that was viewed very negative by the worldwide. There was so many discriminations and harsh commitment toward American America. Even though African American gain freedom for being slave, equality was not granted by the white people. Essentially, the Civil Rights Movement was an important time during the 1950’s and 1960’s that helps eliminated segregation and gain equal rights for all African American citizens. Many leaders such as Martin Luther King, Rosa parks, Malcom X, and Andrew Goodman put themselves at risk. Their effort and commitment ended the discrimination against black African Americans, and finally gain freedom and equality. To begin with, the Jim Crow was a system of segregation and discrimination against black African Americans, which restricted equal right as white Americans. â€Å"Jim Crow the segregation ofShow MoreRelatedThe Right Side Of History : The Civil Rights Movement1228 Words   |  5 PagesOn the Right Side of History: The Civil Rights Movement Open for interpretation, freedom is one of the most resonating and powerful words to Americans. The word ‘freedom’ has been utilized as a tool for social justice; however, due to its versatility, it may also be used as a weapon of destruction. 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