20+Oxidation+and+Reduction

=Objectives= 20.1 20.2 20.3
 * How is the gain or loss of oxygen in a chemical reaction linked to oxidation and reduction?
 * How is the gain or loss of electrons linked to oxidation and reduction?
 * What happens to iron when it corrodes?
 * What is the general rule for assigning oxidation numbers?
 * How are oxidation and reduction defined in terms of a change in oxidation number?
 * How are oxidation numbers used to identify redox reactions?
 * How are changes in oxidation numbers used to balance a redox equation?
 * What is the procedure for balancing a redox equation using half-reactions?

=Outlined Notes= Chapter 20 Oxidation-Reduction Reactions I. The Meaning of Oxidation and Reduction A. What Are Oxidation and Reduction? 1. Oxygen and Redox a. The substance gaining oxygen is oxidized, while the substance losing oxygen is reduced. b. **__Oxidation-reduction reactions-__** also known as redox reactions 2. Electron Shift in Redox Reactions a. **__oxidation-__** is now defined to mean complete or partial loss of electrons or gain of oxygen. b. **__reduction-__** now defined to mean complete or partial gain of electrons or loss of oxygen. 3. Redox Reactions That Form Ions a. Losing electrons is oxidation. Gaining electrons is reduction. b. **__reducing agent-__** the substance that loses electrons c. **__oxidizing agent-__** the substance that accepts electrons 4. Redox With Covalent Compounds B. Corrosion 1) Iron, a common construction metal often used in the form of the alloy steel, corrodes by bein oxidized to ions of iron by oxygen. 1. Resistance to Corrosion 2. Controlling Corrosion

II. Oxidation Numbers




 * ** L ** osing ** E ** lectrons is ** O ** xidation
 * ** G ** aining ** E ** lectrons is ** R ** eduction

=Reference Pages= //Typical Reactions of Main Group Metals//

//Agent// ||  ||   ||   || //Oxidizing// //Agent// ||
 * //Reaction// ||  ||   ||   || //Reducing//


 * 2 Na + Cl2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

2 NaCl ||  ||   ||   || Na ||   ||   ||   || Cl2 ||


 * 2 K + H2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

2 KH ||  ||   ||   || K ||   ||   ||   || H2 ||


 * 4 Li + O2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

2 Li2O ||  ||   ||   || Li ||   ||   ||   || O2 ||


 * 2 Na + O2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

Na2O2 ||  ||   ||   || Na ||   ||   ||   || O2 ||


 * 2 Na + 2 H2O [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

2 Na+ + 2 OH- + H2 ||  ||   ||   || Na ||   ||   ||   || H2O ||


 * 2 K + 2 NH3 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

2 K+ + 2 NH2- + H2 ||  ||   ||   || K ||   ||   ||   || NH3 ||


 * 2 Mg + O2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

2 MgO ||  ||   ||   || Mg ||   ||   ||   || O2 ||


 * 3 Mg + N2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

Mg3N2 ||  ||   ||   || Mg ||   ||   ||   || N2 ||


 * Ca + 2 H2O [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

Ca2+ + 2 OH- + H2 ||  ||   ||   || Ca ||   ||   ||   || H2O ||


 * 2 Al + 3 Br2 [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

Al2Br6 ||  ||   ||   || Al ||   ||   ||   || Br2 ||


 * Mg + 2 H+ [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

Mg2++ H2 ||  ||   ||   || Mg ||   ||   ||   || H+ ||


 * Mg + H2O [[image:http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch9/graphics/rarrow.gif width="17" height="9" align="center" caption=">"]]

MgO + H2 ||  ||   ||   || Mg ||   ||   ||   || H2O ||

=Practice Problems=

=Assignments=

=Labs=

=Sample Test=

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