<p> Oxidation-Reduction Reactions</p><p>Background Oxidation-reduction reactions involve the oxidation and the reduction of different chemical species during a chemical reaction. This type of reaction is made possible through electron exchange. A net ionic equation represents this exchange of electrons and is a balanced chemical reaction. Complete equations represent all of the ions and compounds present during the chemical reaction. If you cannot detect any chemical reaction with your senses, then writing a complete or ionic equation is not necessary. If there is no chemical reaction, then there is no electron transfer. Remember, when you write chemical equations, a metal is written alone, and hydrogen, oxygen, nitrogen, and the halogens are diatomic with a net charge of zero.</p><p>KNOW: What do you know about oxidation and reduction reactions?</p><p>Objectives -Identify oxidation and reduction species. -Identify chemical reactions with your senses. -Construct complete and ionic chemical equations. Procedure Part 1: Metals with Acids 1. Place 5 mL 6 M HCl in 4 different test tubes. 2. Place the indicated metals in the acid, and record your observations. 3. Write the complete and net ionic reactions for the reactions that occurred. Make sure that all of your chemical equations are balanced.</p><p>Metal Observations Equations</p><p>EX:Ca H2 gas produced Ca + 2HCl  CaCl2 + H2 (complete reaction)</p><p>+ +2 Ca + 2H  Ca + H2 (net ionic reaction)</p><p>Cu</p><p>Mg</p><p>Sn</p><p>Zn Procedure Part 2: Metals with Metals 1. Add about 4 mL of your metallic solution to a test tube. 2. Place a piece of the indicated metal in the solution and record your observations. 3. Write the complete and net ionic reactions for the reactions that occurred. Make sure all of your chemical reactions are balanced.</p><p>Observations</p><p>Solution ions: Cu +2 Fe +2 Mg +2 Zn +2</p><p>Metal</p><p>Cu</p><p>Mg</p><p>Zn</p><p>Sn</p><p>Ca</p><p>Equations Complete equations Electron Transfer</p><p>+2 +2 Ca+Mg(NO3)2  Ca(NO3)2 + Mg Ca + Mg  Ca + Mg WHAT: What did you learn about oxidation-reducation reactions?</p><p>Answer two of the Analysis questions with complete sentences. 1.Describe two oxidation-reduction reactions that occur in everyday life.</p><p>2.How could you test for the H2 gas present in the reactions of a metal with HCl?</p><p>3.What is occurring with the oxidized species in a chemical reaction? What is ocurring with the reduced species in a chemical reaction?</p><p>LEARN: What do you still want to learn about oxidation-reduction reactions? </p>