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Physical Equilibrium
Chemical Equilibrium
Le Chatelier's
Equilibrium Constant
Randomness
100
What are two physical phase changes that occur reversibly involving solid and liquid?
Melting and Freezing
100
Chemical Equilibrium is a dynamic process (T/F)
True
100
According to Le Chatelier, what are the 3 "stressors"?
Concentration, Volume/Pressure, and Temperature.
100
Write the Kc for the equation HCl (aq) + CaCO3 (s) <--> CaCl2 (aq) + CO2 (g)
Kc = [CO2][CaCl2] / [HCl]
100
Which way will the reaction shift if the concentration of SO3(g) decreases in 2SO2(g)+O2(g)<--->2SO3(g)+heat
Right
200
What are two physical phase changes that occur reversibly involving liquid and gas?
Vaporization and Condensation
200
In order for chemical equilibrium to occur, the concentrations of the products and reactants must equal (T/F)
False
200
In the reaction, A + B <--> C + D, What will happen to the equilibrium if excess D is added to the system?
The reaction will shift towards the reactants in order to consume the excess D added and produce more A and B.
200
Using the equation, 2NO2 (g) <--> N2O4 (g) 2 NO2= .500M N2O4= .025M Calculate Kc.
Kc = .100
200
What change in pressure will shift the reaction to the left? 2SOs(g)+O2(g)<--->2SO3(g) Explain.
Increase.
300
Equilibrium is a state or condition in which two opposing processes take place at the same rate (T/F)
True
300
What is the role of a catalyst (in terms of equilibrium)?
A catalyst does not affect equilibrium, it only affects the rate.
300
At the end of an equilibrium reaction, the solution is very hot. Explain this reaction in terms of heat (exothermic/endothermic).
In order for the reaction to be hot to the touch at the end of a reaction, heat has to be given off by the system making it exothermic. An exothermic reaction will have heat as its product.
300
One will be able to determine the direction of the reaction by looking at the rate (T/F)
False
300
What is the effect of increasing the volume of a closed container equivalent to?
Decreasing the pressure.
400
In an equilibrium reaction such as: NaCl(s) <--> Na+(aq) + Cl-(aq); At equilibrium, the rate of dissolving will equal the rate of _________.
Crystallization
400
What is homogeneous equilibrium? Give an example.
States of reactants and products are the same. Examples may vary.
400
Summarize Le Chatelier's Principle.
“A dynamic equilibrium tends to respond so as to relieve the effect of any change in the conditions that affect the equilibrium.”
400
What does it mean if K < 1
Reactants are favoured.
400
What effect will adding more reactants or decreasing the products result in?
Shift to the right.
500
What does the term MACROSCOPIC change mean?
A change that can be seen with the naked eye (not at the molecular level)
500
What is heterogeneous equilibrium? Give an example.
States of reactants and products are different. Examples may vary.
500
2SO3(g) + 197 kJ <--> 2SO2(g) + O2(g) In what direction will equilibrium shift if we increase the temperature?
Right
500
What does it mean if K>1?
Products are favoured.
500
Explain the difference between a reaction intermediate and an activated complex.
Answers will be judged by teacher.