EQUILIBRIUM EQUILIBRIUM n Equilibrium occurs when in a
EQUILIBRIUM
EQUILIBRIUM n Equilibrium occurs when, in a reaction n reactants form products n AND n products n at n reform reactants the same rate Equilibrium is symbolized by using a double-headed arrow in the chemical equation. n⇄
![EQUILIBRIUM CO(g) + H 2 O(g) ⇄ CO 2(g) + H 2(g) [CO] or](http://slidetodoc.com/presentation_image_h2/a2e78fa21562bc3f6bc731c5d109add6/image-3.jpg "EQUILIBRIUM CO(g) + H 2 O(g) ⇄ CO 2(g) + H 2(g) [CO] or")
EQUILIBRIUM CO(g) + H 2 O(g) ⇄ CO 2(g) + H 2(g) [CO] or [H 2 O] [CO 2] or [H 2] Concentration n Time Equilibrium
![EQUILIBRIUM [CO] or [H 2 O] Concentration [CO 2] or [H 2] Equilibrium Time](http://slidetodoc.com/presentation_image_h2/a2e78fa21562bc3f6bc731c5d109add6/image-4.jpg "EQUILIBRIUM [CO] or [H 2 O] Concentration [CO 2] or [H 2] Equilibrium Time")
EQUILIBRIUM [CO] or [H 2 O] Concentration [CO 2] or [H 2] Equilibrium Time n n The blue graph shows the reactants being used up. The red graph shows the products being produced. At the dotted line, equilibrium is achieved. At equilibrium, the reaction “stops”. n The forward and reverse reactions are occurring at the same rate.
EQUILIBRIUM n n n Details about the amount of substances can be calculated using the EQUILIBRIUM CONSTANT: For the reaction: x. REACTANTS ⇄ y. PRODUCTS [ ] mean “concentration (in molarity) of” whatever is inside them If there is more than one reactant, the concentration of each reactant is taken to its own exponent, then all are multiplied. If there is more than one product, the concentration of each product is taken to its own exponent, then all are multiplied.
EQUILIBRIUM n If you have more than one reactant or product, their concentrations are multiplied in the equilibrium constant: 2 A + 3 B ⇄ C n n Construct the equilibrium constant expression for the above reaction at equilibrium. [C] Keq = 2 3 [A] [B] Remember, coefficients in the balanced equation become exponents in the equilibrium constant.
EQUILIBRIUM n n Solids and liquids do not appear in the equilibrium constant expression. Only gases and dissolved substances appear in the expression. 2 A(s) + 3 B(g) ⇄ C(g) Construct the equilibrium constant expression for the above reaction at equilibrium. [C] Keq = [B]3
EQUILIBRIUM n Interpreting n If Keq: Keq > 1, then the reaction favors more product formation. n If Keq < 1, then the reaction favors more reactant formation.
EQUILIBRIUM n Relationship to Acids/Bases: n Weak acids/bases have a Keq value that can be calculated. n Strong acids/bases have a Keq that is infinitely large. They dissociate completely leaving no reactant in solution.
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