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Learn about synthesis, decomposition, single displacement, double displacement, and combustion reactions. Understand the nature of reversible reactions, equilibrium, and reaction rates with activation energy. Discover ways to increase reaction rates and the role of catalysts and inhibitors.
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1. Synthesis 2 substances combine to form a compound. Example: 4Fe + 3O2 2Fe2O3 2 reactants 1 product
2. Decomposition A COMPOUND BREAKS DOWN INTO 2 OR MORE SIMPLER SUBSTANCES NH4NO3 N2O + H2O 1 reactant More than 1 product
3. Single Displacement • Rxn where 1 element takes the place of another • Example Fe + CuSO4 FeSO4 + Cu Element, compound Element, compound
4. Double Displacement • Rxn where the + portion of 2 ionic compounds are interchanged • Example: Pb(NO3) 2 + 2KI KNO3 + PbI2 compound, compound compound, compound
5. Combustion • Rxn where a substance rapidly combines with Oxygen to form 1 or more oxides • Example: 2C2H2 + 5O2 4CO2 + 2H2O + Energy O is a reactant
A. Reversible Rxns • Can change direction • Equilibrium – rxn that automatically reverses & there is no overall change in the amount of products or reactants.
Reversible Rxns Cont. 3. Example: CaCO3(s) CaO(s) + CO2 (g) limestone lime 4. The double arrow shows that the rxn can go either way.
5. Equilibrium can “disturbed” in order to increase the yield of desired product in a rxn. Example: CaCO3 CaO + CO2 a. If you take out the CO2 the rxn will shift right to produce more lime
b. Adding E can push a rxn to the left or right. 1. Example: 3C + 2Al2O3(s) + E 4Al + 3CO2 (g) Endo to the right Exo to the left When you add more E, more product is formed. 2. Example: N2 + H2 NH3 + E Exo to the right Endo to the left Adding more E pushes the rxn left
B. Reaction Rate • Activation Energy –the amt of E required to make a rxn occur
Ways to increase Reaction rates • Raising temps • Increasing Concentration- amt of a substance present in a given volume Ex: fanning flames 3. If gases are involved, the rate of rxn can be increased by increasing pressure.
Rxn Rate Cont. • Increasing Surface Area- crushing or breaking substances into smaller pieces increase rxn rates. • Add a Catalyst – substance that speeds up the rxn rate without being permanently changed or used up itself In the body they are called enzymes
Slowing Reactions • Do the opposite of any way to speed rxns up. • Inhibitor – slows a rxn without participating