Irreversible Reactions Reactions completely change reactants into products
§ Irreversible Reactions § Reactions completely change reactants into products § Example: Once it is chocolate, it will always only be chocolate a. A + b. B -> c. C + d. D
§ Most reactions are reversible reactions § Both forward and reverse directions § Example: Changes into chocolate, but also changes back into cacao and sugar at the same time § Product is made, but some of the product is also changing back to reactants a. A + b. B -> c. C + d. D
§ Reversible Reactions 1. Both reactants and products exist together as a mixture 2. Ration of reactants to products depends on speeds (rates) of forward and reverse reactions 3. Changing rate of either part changes ratio of products & reactants
§ Chemical equilibrium§ forward & reverse occur at same rate, balance each other
§ Chemical equilibrium is dynamic. Particles involved constantly move and react. § Ethane (C 2 H 6) reacts with Oxygen to produce water and carbon dioxide 2 C 2 H 6 + 7 O 2 6 H 2 O + 4 CO 2 § But some water also collides with carbon dioxide to form ethane and oxygen 6 H 2 O + 4 CO 2 2 C 2 H 6 + 7 O 2
§ Products form faster, so product favored reaction
§ Can also change arrow size to show which is favored
§ Good to use something called an ICEbox [A] Initial Change Equilibrium [B] [C]
§ [H 2] Initial Change Equilibrium [I 2] [HI]
§ Initial Change Equilibrium [H 2] [I 2] [HI] 0. 200 0
§ [H 2] [I 2] [HI] Initial 0. 200 0 Change -x -x + 2 x Equilibrium
§ [H 2] [I 2] [HI] Initial 0. 200 0 Change -x -x + 2 x Equilibrium 0. 200 – x 2 x
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