'Chemical Reaction Essay\r'

'chemical substance substance Reactions Lab\r\nObjectives: 1. To read a variety of chemical replys including precipitation, acid-base, gas forming, and oxidoreduction reactions. 2. To pick out the products formed in these reactions and fill up the chemical substance miscell whatsoevers in terms of fit chemical comparisons and gelt garret equations. 3. To identify the species being oxidised and reduced in oxidisation-reduction reactions and determine which species is the oxidizing agent and the lessen 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 iodine reactant changes places with the anion of the other reactant. most exchange reactions take place in aqueous resolving powers. Other types of exchange reactions allow in p recipitation and gas forming reactions. When a solution of lead (II) nitrate and sodium sulfate be mixed, you observe that a precipitous is formed.\r\nWhat is the identity of the precipitate and what is the match molecular(a) equation and elucidate dome equation describing this reaction? To determine the answers to these questions, you must get-go be able to salve the pose 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? hotshot preemptnot know the answer to this question without employ the solubility rules (Tro text, Table 4.1, p. 136). By employ this table it can be persistent 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 th is equation balanced? No. So, it now gather ups 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 create verbally as a flesh out ionic equation and consequently the spectator ions (the under getd 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)\r\n oxidoreduction (redox) reactions are another important differentiate of\r\nchemical reactions. In redox reactions electrons are transferred from one substance to another. For example, if a squealer wire is placed in a solution of silver nitrate a redox reaction occurs and silver admixture is formed along with hog (II) nitrate. oxidization numbers: (0) (+1) (+2) (0) Molecular equation: Cu (s) + 2 AgNO3 (aq) ↠Cu(NO3)2 (aq) + 2 Ag (s) (0) (+1) (+2) (0)\r\n clear ionic equation:\ r\nCu (s) + 2 Ag+ (aq) ↠Cu2+ (aq) + 2 Ag (s)\r\nThe 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 trance the silver ion is being reduced. pig is therefore the reducing agent while silver nitrate is the oxidizing agent.\r\nPROCEDURE YOU use up TO WEAR GOGGLES AT alone TIMES WHILE PERFORMING THIS EXPERIMENT. Chemical bluster can be prone of in the waste beakers supplied in the hoods. pull up stakes I: Exchange Reactions: 1. Obtain 7 small, new raise organ pipes. For the purposes of this lab, the exam tubes accept only be clean, not all dry. A hose connected to the origin supply in the hood whitethorn be used to quickly back away most water from the exam tubes. 2. key 10 drops of 0.5 M CaCl2 into to severally one of the 7 test tubes. 3. Next, contribute 10 drops of 0.5 M solutions of each of the following solutions to the indicated test tubes, and eternize your observations. Allow at least 5 minutes for reactions to occur before disposing your solutions. streak Tube 1 2 MgSO4 (NH4)2C2O4 3 KNO3 4 Na3PO4 5 KBr 6 NaOH 7 K2CO3\r\n4. 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 surface of a small pea of bake 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.\r\n7. Put 10 drops of 0.5 M nitric acid and 10 drops of 0.5 M phosphorous 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 caustic 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.\r\n occasion II: REDOX REACTIONS: 8. Add a small chip of zinc to a test tube containing 30 drops of 6 M HCl and temperament what happens. 9. Add a 1 inch piece of copper wire to a test tube containing 30 drops of 6 M HCl and demean 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 atomic number 12 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 at once AT THE BURNING MAGNESIUM. LABORATORY handle Students provide write an individual or group laboratory report at the discretion of the professor. Includ e the following instruction in your laboratory report, due at the beginning of the laboratory period abutting week. 1. Title. Title of the experiment, your constitute, your partner’s name and the date the laboratory was performed. 2. Introduction. This will be your opportunity to practice writing creations. The entrée to the lab should be about chemical reactions in general (why they are important, examples of particular proposition 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. observational Details. A description of the procedure you followed to bring out the experimental data and results. Alternatively, you whitethorn computer address 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 fragment as well as any observations from the remainder of the reactions in\r\nparts 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)], subsequently each reactant and product. In addition,\r\nfor 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 house any additional insights that you have into the reaction (was it easy/hard to observe, interesting things to not e, etc.). You will also want to correlate things knowing 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 select by email, please attach a single file with a file name convention of Lastname Firstname Reactions and a subject line of â€Å"Chem 1061: Reactions Lab”.\r\n'