Kinetics and Equilibrium Flashcards
How are values of x and y determined in a rate law equation?
Eperimentally
What is the equation for rate law expressions
rate=k[A]^x[B]^y
Equation for the equilibrium constant Kc for equation:
aA + bB cC + dD
Kc= [C]^c[D]^d / [A]^a[B]^b
What is excluded from equilibrium expressions?
pure solids and pure liquids
If Keq > 1
the equilibrium mixture will contain very little of the reactants compared to the products
If Keq < 1
the equilibrium mixture will contain very little of the products compared to the reactants
If Keq = 1 (approx)
the equilibrium mixture will have approximately equal concentrations of products and reactants
For the equation:
A + B C
What happens if more A is added?
Shifts to the right
For the equation:
A + B C
What happens if more B is added?
Shifts to the right
For the equation:
A + B C
What happens if C is taken away?
Shifts to the right
For the equation:
A + B C
What happens if pressure is applied?
if they are gases they shift to the right because it has less moles of gas
For the equation:
A + B C
What happens if volume is reduced?
if they are gases they shift to the right because it has less moles of gas
For the equation:
A + B C + heat
If the temperature is reduced?
shifts toward whichever side has heat, in this care the right
For the equation:
A + B C
What happens if more C is added?
It shifts towards the left
For the equation:
A + B C
What happens if A is removed?
It shifts towards the left
For the equation:
A + B C
What happens if B is removed?
It shifts towards the left
For the equation:
A + B C
What happens if pressure is reduced?
Shifts to the left (if gases, because more moles)
For the equation:
A + B C
What happens if the volume is increased?
Shifts to the left (if gases, because more moles)
For the equation:
A + B C + heat
What happens if the temperature is increased?
shifts towards whatever way will decrease the heat, in this case the left
Collision Theory of Chemical Kinetics
the rate of the reaction is proportional to the number of collisions per second between reacting molecules, but molecules must collide with sufficient energy and in the right orientation for the collision to be successful
Transition State Theory
The transition state that molecules pass through when forming products has a higher energy then the reactants and the products and activation energy is needed to achieve this state and more energy is needed to overcome this state
Negative Delta G
exergonic reaction
Positive Delta G
endergonic reaction
Rate law includes concentrations of
REACTANTS ONLY
Zero Order Reactions
the rate of formation of products is independent of changes in concentrations of reactants
rate=k
negative, linear representation on a concentration vs. time graph
First Order Reactions
the rate of formation of products is dependent on one of the reactants
rate=k[A]^1
negative linear representation on a ln[A] vs time graph
Second Order Reactions
the rate of formation of products is dependent on either two reactants or the square of one of the reactants
Keq for
aA + bB cC + dD
Keq = [C]^c [D]^d / [A]^a [B]^b
Kc can be used for gases
do not include pure elements
Reaction Quotient (Q)
used to determine where in the reaction we are in relation to the equilibrium state
Q > Keq
forward reaction has exceeded equilibrium
Q = 1
reaction is in dynamic equilibrium
Q < 1
forward reaction has not yet reached equilibrium
Reverse Equilibrium Constant
1/Keq
Kinetic Product
formed at lower temperature, formed faster, but less stable
Thermodynamic Product
formed at higher temperature, formed slower, but more stable
