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Chem 178 Chapter 15
Chemical Equilibrium Review
Question | Answer |
---|---|
15.1) What is the point at which the concentrations of all species are constant? | Chemical equilibrium |
15.1) In a rate law, are the concentrations of just reactants, just products, or both included? | Reactants |
15.1) What type of equilibrium exists when the rates of the forward and reverse reactions are equal? | Dynamic |
15.2) What is K subscript c? | The equilibrium constant in terms of concentration |
15.2) What is K subscript p? | The equilibrium constant in terms of pressure |
15.2) In an equilibrium-constant expression, is K subscript c equal to the concentration of reactants over the the concentration of products? | No, concentration of products over concentration of reactants |
15.2) Which phases of matter are eliminated from equilibrium-constant expressions? | Solids and liquids |
15.2) In the general expression relating K subscript c and K subscript p, how is the change in n calculated? | Moles of gaseous product - moles of gaseous reactant |
15.3) If K >> 1, do products or reactants dominate at equilibrium? | Products |
15.3) If K << 1, do products or reactants dominate at equilibrium? | Reactants |
15.3) How is the equilibrium constant for the forward reaction related to the equilibrium constant for the reverse reaction? | Reciprocals |
15.3) How is the equilibrium constant for a net reaction of two or more steps determined? | Product of K's for individual steps |
15.4) What type of equilibria has all reactants and products present in the same phase? | Homogeneous |
15.4) What type of equilibria has products and reactants present in different phases? | Heterogeneous |
15.6) What is used to determine the value of the equilibrium expression, when the system is not at equilibrium? | Q, the reaction quotient |
15.6) How are Q and K related when the system is at equilibrium? | Q = K |
15.6) How are Q and K related when the forward reaction must occur to reach equilibrium? | Q < K |
15.6) How are Q and K related when the reverse reaction must occur to reach equilibrium? | Q > K |
15.7) What is the term for a system that will shift its equilibrium position to counteract the effects of a disturbance? | Le Chatelier's Principle |
15.7) What disturbances does Le Chatelier's Principle include? | Change in: temperature, pressure, concentration |
15.7) If you remove product from a system at equilibrium, which way does the reaction proceed? | Toward the product |
15.7) If the pressure is increased in a gaseous system, which way does the reaction proceed? | Toward the direction with fewer moles |
15.7) What happens to K when increasing the temperature of an endothermic reaction? | Increases |
15.7) What happens to K when increasing the temperature of an exothermic reaction? | Decreases |
15.7) How does a catalyst speed up a reaction? | Lowers activation energy |