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Decomposition and Redox. Decomposition and Redox: At the conclusion of our time together, you should be able to:. Identify decomposition chemical reactions Show the change in oxidation numbers for this type of reaction. R U Whining????!!!!. Simple Reactions. Synthesis (Combination).
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Decomposition and Redox:At the conclusion of our time together, you should be able to: Identify decomposition chemical reactions Show the change in oxidation numbers for this type of reaction
Simple Reactions Synthesis (Combination) Decomposition Single Replacement Double Replacement
Synthesis A + B A B Decomposition A + B A B Single Replacement + + A B C A C B Double Replacement + + A B C D A D C B
Synthesis A + B A B Decomposition A + B A B Single Replacement + + A B C A C B Double Replacement + + A B C D A D C B
2. Decomposition Reactions • Decomposition reactionsoccur when a compound breaks up into the elements or in a few to simpler compounds • 1 Reactant Product + Product • In general: AB A + B • Example: 2 H2O 2H2 + O2 • Example: 2 HgO 2Hg + O2
2. Decomposition Reactions • For Decomposition reactions to occur we need energy as a catalyst in the form of: • Heat • Light • Electricity • Mechanical shock • Or a chemical catalyst
Decomposition Reactions • Another view of a decomposition reaction:
Decomposition Exceptions • Carbonates and chlorates are special case decomposition reactions that do not go to the elements. You should be able to recognize these as decomposition only. • Carbonates (CO32-) decompose to carbon dioxide and a metal oxide • Example: CaCO3 CO2 + CaO • Chlorates (ClO3-) decompose to oxygen gas and a metal chloride • Example: 2 Al(ClO3)3 2 AlCl3 + 9 O2
Decomposition Exceptions • Ternary acids will tend to decompose to water and the nonmetal oxide. • Example: H2SO3 H2O + SO2 • There are other special cases, but we will not explore those in this class
Practice • Predict the products. Then, write and balance the following decomposition reaction equations: • Solid Lead (IV) oxide decomposes PbO2(s) • Aluminum nitride decomposes AlN(s) Pb + O2 Al + N2
Practice of Decomposition and Redox • Predict the products, balance the following reactions and show the change in oxidation numbers : H2O H2 + O2 2 H2O 2 H2 + O2 Each H gains 1e- reduction, oxidizing agent Each Oloses 2e- oxidation, reducing agent
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Decomposition and Redox:Let’s see if you can: Identify decomposition chemical reactions Show the change in oxidation numbers for this type of reaction
Practice Identify the type of reaction for each of the following decomposition reactions, and write the balanced equation: BaCO3(s) NI3(s) BaO + CO2 N2 + I2 2, 1, 3
Practice of Decomposition and Redox • Predict the products, balance the following reactions and show the change in oxidation numbers: FeO Fe + O2 2 FeO 2 Fe + O2 Each Fe(II) gains 2e- reduction, oxidizing agent Each Oloses 2e- oxidation, reducing agent
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