Chemical Reaction Essay Example for Free

Chemical Reaction Essay Chemical Reactions Lab Objectives: 1. To examine a variety of reactions including precipitation, acid-base, gas forming, and oxidation-reduction reactions. 2. To identify the products formed in these reactions and summarize the chemical changes in terms of balanced chemical equations and net ionic equations. 3. To identify the species being oxidized and reduced in oxidation-reduction reactions and determine which species is the oxidizing agent and the reducing agent. Chemical equations represent what occurs in a chemical reaction. For example, the equation HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) describes an acid-base reaction, a type of exchange reaction in which the driving force is the formation of water. In an exchange reaction, the anion of one reactant changes places with the anion of the other reactant. Most exchange reactions take place in aqueous solutions. Other types of exchange reactions include precipitation and gas forming reactions. When a solution of lead (II) nitrate and sodium sulfate are mixed, you observe that a precipitate is formed. What is the identity of the precipitate and what is the balanced molecular equation and net ionic equation describing this reaction? To determine the answers to these questions, you must first be able to write the CORRECT FORMULAS for the reactants and the products for this reaction. The following represents these formulas in an unbalanced chemical equation: Pb(NO3)2 (aq) + Na2SO4 (aq) → PbSO4 + NaNO3 Which product is the precipitate? One cannot know the answer to this question without using the solubility rules (Tro text, Table 4.1, p. 136). By using this table it can be determined that PbSO4 is an insoluble salt whereas NaNO3 is soluble. Consequently, one can write the subscripts for the products indicating which product is the precipitate. Pb(NO3)2 (aq) + Na2SO4 (aq) → PbSO4 (s) + NaNO3 (aq) Is this equation balanced? No. So, it now needs to be balanced. Pb(NO3)2 (aq) + Na2SO4 (aq) → PbSO4 (s) + 2 NaNO3 (aq) To write the net ionic equation, the above equation should be written as a complete ionic equation and then the spectator ions (the underlined ions) are cancelled. Pb2+ (aq) + 2 NO3- (aq) + 2 Na+ (aq) + SO42- (aq) → PbSO4 (s) + 2 Na+ (aq) + 2 NO3- (aq) So, the net ionic equation for this precipitation reaction is: Pb2+ (aq) + SO42- (aq) → PbSO4 (s) Oxidation-reduction (redox) reactions are another important class of chemical reactions. In redox reactions electrons are transferred from one substance to another. For example, if a copper wire is placed in a solution of silver nitrate a redox reaction occurs and silver metal is formed along with copper (II) nitrate. Oxidation numbers: (0) (+1) (+2) (0) Molecular equation: Cu (s) + 2 AgNO3 (aq) → Cu(NO3)2 (aq) + 2 Ag (s) (0) (+1) (+2) (0) Net ionic equation: Cu (s) + 2 Ag+ (aq) → Cu2+ (aq) + 2 Ag (s) The oxidation numbers for the metallic elements in this equation (See oxidation number rules, Tro text, p. 148) show us that copper metal is being oxidized while the silver ion is being reduced. Copper is therefore the reducing agent while silver nitrate is the oxidizing agent. PROCEDURE YOU NEED TO WEAR GOGGLES AT ALL TIMES WHILE PERFORMING THIS EXPERIMENT. Chemical waste can be disposed of in the waste beakers supplied in the hoods. Part I: Exchange Reactions: 1. Obtain 7 small, clean test tubes. For the purposes of this lab, the test tubes need only be clean, not totally dry. A hose connected to the air supply in the hood may be used to quickly remove most water from the test tubes. 2. Place 10 drops of 0.5 M CaCl2 into each of the 7 test tubes. 3. Next, add 10 drops of 0.5 M solutions of each of the following solutions to the indicated test tubes, and record your observations. Allow at least 5 minutes for reactions to occur before disposing your solutions. Test Tube 1 2 MgSO4 (NH4)2C2O4 3 KNO3 4 Na3PO4 5 KBr 6 NaOH 7 K2CO3 4. Dispose of the solutions and any precipitates in the waste beakers located in the hoods. Wash your test tubes with soap and water. Rinse with tap water, then deionized water. 5. Add an amount equivalent to the size of a small pea of baking soda (sodium hydrogen carbonate) to a clean test tube. Add 10-20 drops of vinegar. (Vinegar is an aqueous solution of acetic acid, HC2H3O2). Record your observations. 6. IN THE HOOD, add an amount equivalent to the size of a small pea of sodium sulfite, Na2SO3, to a test tube. Add 10-20 drops of 6 M HCl. Record your observations. 7. Put 10 drops of 0.5 M nitric acid and 10 drops of 0.5 M phosphoric acid into separate test tubes. Add 1 drop of phenolphthalein to each test tube. Add drops of dilute (0.5 M) sodium hydroxide solution into each of the test tubes until a permanent color change is observed. (NOTE: Phenolphthalein is an acid-base indicator that is colorless in acidic and neutral solutions, but pink in basic solutions). HINT: When writing your net ionic equations: nitric acid is a strong acid while phosphoric acid is a weak acid. Part II: REDOX REACTIONS: 8. Add a small piece of zinc to a test tube containing 30 drops of 6 M HCl and record what happens. 9. Add a 1 inch piece of copper wire to a test tube containing 30 drops of 6 M HCl and record what happens. (Is copper an active metal or inactive metal with HCl? Look up an activity series of metals online to check). 10. IN THE HOOD, take a 2 inch piece of magnesium ribbon and hold it with a pair of crucible tongs. Light the magnesium metal with a Bunsen burner and record your observations. DO NOT LOOK DIRECTLY AT THE BURNING MAGNESIUM. LABORATORY REPORT Students will write an individual or group laboratory report at the discretion of the professor. Include the following information in your laboratory report, due at the beginning of the laboratory period next week. 1. Title. Title of the experiment, your name, your partners name and the date the laboratory was performed. 2. Introduction. This will be your opportunity to practice writing introductions. The int roduction to the lab should be about chemical reactions in general (why they are important, examples of specific types of chemical reactions such as combustion, precipitation, redox, etc.), not about how to write and balance an equation. For complete guidelines, go to â€Å"Laboratory Reports† on the Chem 1061 website. 3. Experimental Details. A description of the procedure you followed to produce the experimental data and results. Alternatively, you may reference the procedure by citing the URL’s (web addresses). 4. Results. A table or tables of your experimental data, clearly labeled with the proper units. Remember to use subscripts and superscripts where appropriate (examples: cm3 or H2O). A neat table which includes your observations from the precipitation reactions (steps 2-3) should be included in a results section as well as any observations from the remainder of the reactions in parts I and II. 5. Discussion and Conclusion. For all the reactions observed (exchange reactions and redox), write the balanced molecular equation and net ionic equation for each reaction. For each reaction, place phase labels, [(s), (l), (g), or (aq)], after each reactant and product. In addition, for the redox reactions in part II, indicate which reactant is the oxidizing agent and which one is the reducing agent. There is no need to write equations for combinations that produced no reaction. For each reaction that you observed and for which you write equations, you may provide any additional insights that you have into the reaction (was it easy/hard to observe, interesting things to note, etc.). You will also want to correlate things learned or observed with what you discussed in the introduction about reactions in general. 6. References. Citations and references to any sources you may have used for the introduction or to perform, complete, or analyze the results of the lab. 7. Follow your instructor’s directions for submission of this lab report. If you submit by email, please attach a single file with a filename convention of Lastname Firstname Reactions and a subject line of â€Å"Chem 1061: Reactions Lab†.

Michael Jordan :: Free Essays

Michael Jordan Michael Jordan is an American Professional Basketball Player . I picked Michael for my biography because I consider him to be the best basketball player in the NBA . Michael is recognized for his spectacular ball handling skills and for his outrageous dunks . He is also the leading scorer in the NBA , and a winner of three NBA most valuable player award in 1988,1991, and 1992 . Jordan was born in Brooklyn , New York , and raised in Wilmington , North Carolina . He accepted a basketball scholarship at the University of North Carolina and as a freshman he scored the winning shot in the 1982 NCAA championship game .   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  In 1984 Jordan led the U.S. basketball team to victory in the Olympics . After that he left college to play for the Chicago Bulls . Jordan was successful as a professional from his first season , Leading the NBA in the 1984-85 season in points scored . He also was named rookie of the year and started in the All Star game .   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  In the 1986-87 season Jordan became the second player ever to score 3000 points in one season . In the following six seasons he led the NBA in scoring averaging more than 30 points per game . Jordan led the Chicago Bulls to their first NBA championship tittle in 1991, and did it again in 1992 and in 1993 . Jordan retired from basketball in 1994 to play baseball . He only played for about one year but he didn't have what it took to be a baseball player . He came back to play basketball in the middle of the 1995 season to lead the Bulls into the first round of the playoffs where they where beat .   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Jordan was the NBA's most valuable player for the 1987- 88 season and again for the 1990-91 and the 1991-92 season . This is the first time a NBA player won for two consecutive seasons .

Racial Profiling Essay

Racial profiling is a big issue. Many people have been victimized because of cops and other high authorities’ senseless attitudes on how to handle the law. What people have to realize is that racial profiling does happen to innocent people who are mostly targeted or pursued because of their race or sometimes even because of their religion. These things can also cause citizens to become very angry and unwilling to cooperate with law enforcement. Racial profiling has been the cause of many outbreaks of riots. There has even been many riots because of innocent people being racial profiled against; causing citizens to become antagonistic, bitter, and hateful towards the law. This can be a problem because they even target good police. The cause of racial profiling can start not only hostile attitudes, but a shift in the views of how police treat citizens. Racial profiling is a method that police and other law enforcement agents use to catch someone who has committed a crime or is about to commit one. It is a controversial method. In fact, even the meaning of racial profiling is controversial† (Kops, Pg. 9). Racial profiling is a very controversial topic, because this topic makes people uneasy to talk about. It’s especially hard for victims who have been racial profiled against because of the memory of their terrible experience. â€Å"In 1942, over 120,000 American were stripped of their business and their homes and incarcerated for the duration of World War II. They had committed no offense. They were convicted of no crime. They were suspected, subjected to curfews, arrested, had their property confiscated, and finally imprisoned because of the color of their skin and their national origin or the national origin of their parents† (Meeks, Pg. ). Situations like this can cause a shift in the government where they have constant issues on how to approach citizens because of the fear of being accused of discriminating against people. This sometimes has citizens wondering is it okay for police to check you if they â€Å"think† you are committing a crime? Well there have been mixed answers when the law is confronted with this question. Also this can cause tension between cops and the law enforcement because of all the animosity and stress of being constantly accused of racial profiling. There have been retired cops who have written books talking about their experience as a cop. Some give details that outsiders wouldn’t know about the cop’s secret jobs. Is it possible that good police are afraid? This could be the reason why; they could also be afraid that if they tell too much they could possibly lose their job. But just as there are good cops, there are also bad cops. Like the ones who harass people for no reason; simply because of the physical features. â€Å"An officer’s daily duties require them to violate the rights of others, without question, on a repeated basis (see video – 2min in). Police routinely fine or jail, at taxpayer expense, people whose crimes lack an actual victim. Whether it is for driving without a license, disorderly conduct or illegal drugs, police are the ones enforcing such laws. More surprisingly is it seems they do so only because they are told to, and believe such violations are acceptable to keep others safe (this doesn’t even include officers who blatantly and knowingly abuse their power)† (Freeman). Is it a thing of giving law enforcement too much power? Many people have many complaints that the law has access to how they suspect if the person is in the wrong. This is a prime example of why there can be a separation between cops. However, often many good cops are targeted for a crooked cop’s bad deed. With this happening it scares away potential cops; who are afraid of this horrible thing happening to them, which has citizens and other authorities on edge. The lack of law enforcement would be a huge problem; without the law the crime rate could possibly reach an ultimate high. Law enforcement is supposed to be put in place as a security, and protection for citizens. But how can you trust them when they also commit crimes. It makes it even harder for citizens to report a crime because they are afraid of what might happen to them. Bad cops are considering somewhat professionals at pulling big schemes. They can pull off these schemes because of the connections they have with even high authorities. Some schemes could be tied to drug trafficking and many other things. But are once they are accused of such heinous crime, why are these issues sometimes forgotten about? It’s like the process of prosecuting these police are constantly kept quiet. Well it’s about time that it’s brought public. â€Å"Negative stereotypical biases of African-American males overshadow any appearances that they are law-abiding citizens. Indeed, in the eyes of many law enforcement officers, an African-American male driving a Mercedes-Benz projects the presumption of illegal activity, not the presumption of a hard working citizen† (Weatherspoon). Keeping these things private can cause more attention to what are they really doing. But no one is taking a stand and asking questions; simply because of fear of becoming a target of the police. â€Å"The term driving while black has been used to describe the practice of law enforcement officials to stop African-American drivers without probable cause. The practice particularly targets African-American males. African-American males are not only singled out while driving, but also while schooling, eating, running for political office, walking, banking, serving as a juror, getting a taxi, shopping, and just being black and a male. The mere fact of being black and male in America is sufficient cause for governmental and private law enforcement officials to abridge the rights of African-American males. This is not to suggest that law enforcement officers can never consider race when performing their job† (Weatherspoon). African American males are not the only people who are targeted. For example, during the Holocaust Jews were killed, beaten, starved, and a lot of other horrific things all because of their religion and race. â€Å"The European Holocaust of the 1930s and 1940s, which cost millions of Jews (and other ethnic groups) their lives, led many Jews and non- Jews alike throughout the world to believe that a Jewish homeland was necessary. During and after World War II, many Jewish refugees found themselves without a nation and with nowhere to go† (Jones, Johnstone, Pg. 358). Racial profiling seems to never have an end. Many cases you hear about how racial profiling still exists ‘til this very day. The question that everyone should be asking is, â€Å"why should a person race, religion, or beliefs determine how they are judged? â€Å"Racial profiling is an abusive practice that targets innocent citizens solely because of the way that they look. It is not an effective law enforcement strategy. Research shows that racial profiling diverts officers’ attention from using actual, objective signs of suspicious behavior to effectively assess situations. Racial profiling erodes trust between law enforcement and its community. As a result, people are less likely to report a crime or work with the police to give information that could apprehend an actual criminal† (Elliot). This statement is true; racial profiling really is not a strategic method. Since this method has been put in place it has done nothing but cause an upset to the community. Communities have had negative feelings towards racial profiling. So why is this still a method? No one seems to ask this important question that could change the law enforcement system. Changing the system could make a better relationship between citizens and law enforcement. Because more citizens may be willing to open up more to the law, without feeling like they can’t trust police. Before this solution could be an option the law enforcement should make an extra effort with making sure that the community knows that they can trust they are truly secured. â€Å"While there have been attempts to end racial profiling in Congress, no bill has successfully been passed. Communities across the country have been subjected to this useless, degrading tactic for too long. Now is the time for Congress to reintroduce and pass comprehensive legislature to end racial profiling† (Elliot). Congress has yet to make any decisions about eliminating racial profiling. But that doesn’t mean that change won’t happen. Racial profiling as stated in within this research paper is a very controversial topic, but it also a sad topic. The way a person can be mistreated just because of the color of their skin. When reading the facts about racial profiling it is saddening to know that a person can be humiliated and tortured over nothing. Victims of racial profiling are caught off guard, because they have no clue of why they have become a target. Some people are targeted because of their religion; for example a Muslim lady could become a target of racial profiling because of her head wrapped. Muslims have became targets ever since the 9/11 incident. â€Å"Since September 11, 2001, members of Arab, Muslim, and South Asian communities have increasingly been searched, interrogated and detained in the name of â€Å"national security†, often times labeled â€Å"terrorism suspects† when in reality many were only charged with misdemeanors or minor immigration violations, if they were charged at all† (Racial Profiling: Face the Truth Campaign). African-American males are also targeted, because of how they present themselves. This can make some African- American males uneasy to go out in public, because of the fear of being watched and seen for the clothes they wear. â€Å"As a result, community members become less likely to assist with criminal investigations or seek protection from police when they themselves are victimized, which makes everyone less safe† (Racial Profiling: Face the Truth Campaign). Communities are now starting to stick together, by not helping the police. Some feel that they should not help the police when the police attack innocent people.

A Brief Timeline of Events in America - 1851-1860

The time between 1851 and 1860 was one of great upheaval in United States history.   1851   The Treaty of Traverse des Sioux is signed with the Sioux Indians. They agree to give up their lands in Iowa and almost all of Minnesota.  The New York Daily Times appears. This will be renamed the New York Times in 1857.  A fire occurs at the Library of Congress, destroying 35,000 books.  Moby Dick is published by Herman Melville.   1852   Uncle Toms Cabin, or Life Among the Lowly is published to great success by Harriet Beecher Stowe.  Uncle Sam appears for the first time in a comic publication in New York.  Franklin Pierce wins the presidency.  The Know Nothing Party is created as a Nativist party opposed to Catholics and immigrants.   1853 The Coinage Act of 1853 is passed by Congress, reducing the amount of silver in coins smaller than a dollar.  Vice President William King dies on April 18th. President Pierce does not appoint a new Vice President for the rest of his time in office.  Mexico gives land along the southern border of present-day Arizona and New Mexico in exchange for $15 million.   1854 The Kansas-Nebraska Act is proposed that would separate the central Kansas Territory into two with the idea that the individuals in the territories would decide for themselves whether they would be free or slave. However, this was opposed to the Missouri Compromise of 1820 because they were both above latitude 36 °30. The act is later passed on May 26th. Eventually this area would be called Bleeding Kansas due to the fighting that would occur over the question of whether the area would be slave or free. In October, Abraham Lincoln gives a speech condemning the act.  The Republican Party is formed by anti-slavery individuals who oppose the Kansas-Nebraska Act.  Commodore Mathew Perry and the Japanese sign the Treaty of Kanagawa opening ports up to trade with the US.  The Ostend Manifesto is created declaring the US right to purchase Cuba or take it by force if Spain does not agree to sell it. When it is published in 1855, it meets with negative public reaction.Walden is publis hed by transcendentalist Henry David Thoreau.   1855 Over the course of the year, a virtual civil war happens in Kansas between pro- and anti-slavery forces.  Frederick Douglass publishes his autobiography entitled My Bondage, My Freedom.  Walt Whitman publishes Leaves of Grass.   1856 Charles Sumner is beaten with a cane by Preston Brooks on the floor of the Senate for an anti-slavery speech. He does not recover fully for three years.  Lawrence, Kansas is the center of violence in Kansas when pro-slavery men kill an anti-slavery settler. Anti-slavery men led by John Brown then retaliate killing five pro-slavery men leading to the name Bleeding Kansas.  James Buchanan is elected as president of the United States.   1857 A pro-slavery legislature in Kansas passes the Lecompton Resolution which an election of delegates to a Constitutional Convention. Buchanan supports the eventual Convention even though it favors pro-slavery forces. It is later approved and then rejected. It becomes a point of contention with the president and Congress. It is finally sent back to Kansas for a popular vote in 1858. However, they choose to reject it. Therefore, Kansas will not be admitted as a state until 1860.  The Supreme Court decides in that slaves are property and that Congress has no right to deprive citizens of their property.  The Panic of 1857 begins. It will last two years and the failure of thousands of businesses.   1858 Minnesota becomes the 32nd state to the enter the Union. It is a free state.  Abraham Lincoln and Stephen Douglas meet in seven debates across Illinois where they discuss slavery and sectionalism. Douglas will win the election, but Lincoln becomes a key figure in national politics.   1859 Oregon joins the Union as a free state.  Silver is discovered in Nevada leads more people out west to make their fortune.  The first American oil well is created when Edwin Drake finds oil in Pennsylvania.  John Brown leads a raid at Harpers Ferry to seize the federal arsenal. He is a devoted abolitionist who wishes to create a territory for fugitive slaves. However, he is captured by a force led by Robert E. Lee. He is found guilty of treason and hanged in Charlestown, Virginia.   1860 The Pony Express begins between St. Joseph, Missouri and Sacramento, California.  Abraham Lincoln wins the presidency after a hard fought campaign centering on the issues of sectionalism and slavery.  South Carolina decides to secede from the Union. The state militia takes over the Federal arsenal at Charleston.