Chapter 14 Flashcards
What is the symbol for the equilibrium constant?
K
A small value of K means that the reaction favours ____.
Reactants
A large value of K means the reaction favours _____.
products
If K is large the concentration of reactants is _____ than the concentration of products at equilibrium.
less
If K is small the concentration of reactants is _____ than the concentration of products at equilibrium.
greater
Reaction rate increases with _____ concentration of products.
increasing
Define reversible
As applied to a reaction, the ability to proceed in either the forward or the reverse direction
Define dynamic equilibrium
The point at which the rate of the reverse reaction or process equals the rate of the forward reaction or process
____ _____ for a chemical reaction is the condition in which the rate of the forward reaction equals the rate of the reverse reaction
Dynamic equilibrium
At equilibrium are the concentrations of the reactants and products equal?
No!!!!!
At equilibrium is the rate of the forward reaction equal to the rate or the reverse reaction?
yes!
Define equilibrium constant (Kc)
The ratio, at equilibrium, of the activities of the products raised to the power of their stoichiometric coefficients to the activities of the reactants raised to the power of their stoichiometric coefficients
The ____ ____ (__) is defined as the ratio of concentrations –at equilibrium– of the products raised to the power of their stoichiometric coefficients divided by the reactants raised to the power of their stoichiometric coefficients.
equilibrium constant (Kc)
The equilibrium constant quantifies the relative concentrations of reactants and products at _____
equilibrium
Define law of mass action
The relationship between the balanced chemical equation and the expression of the equilibrium constant
For gasses the equilibrium constant can be calculated in terms of _____
pressures
Define activity
A measure of deviation from the standard state.
Does the equilibrium constant say anything about how fast a reaction reaches equilibrium?
No. It only says how far a reaction will go to reach equilibrium
If K«_space;1:
_____ reaction favoured
_____ reaction does not proceed very far
reverse
forward
If K»_space; 1:
_____ reaction favoured
_____ reaction proceeds essentially to completion
forward
forward
If K ≈ 1:
_____ direction is favoured
_____ reaction proceeds about halfway
neither
forward (or reverse)
If you reverse the equation, _____ the equilibrium constant.
invert
If you multiply the coefficients in the equation by a factor, ____ the equilibrium constant to the same factor.
raise
If you add two or more individual chemical equations to obtain an overall equation, ____ the corresponding equilibrium constants by each other to obtain the overall equilibrium constant
multiply
We define the _____ _____ (__) as the ratio –at any point in the reaction– of the concentrations of the products raised to the power of their stoichiometric coefficients divided by the reactants raised to the power of their stoichiometric coefficients
reaction quotient (Qc)
For gases the reaction quotient is in terms of ____ _____
partial pressures
What is the reaction quotient for a mixture containing only reactants equal to?
Qc = 0
What is the reaction quotient for a mixture containing only products equal to?
Qc = ∞ (infinity)
At equilibrium the reaction quotient is ____ ____ the equilibrium constant
equal to
At equilibrium the reaction quotient is ____ ____ the equilibrium constant
equal to
When Q < K the reaction…?
goes to the right (towards products).
When Q > K the reaction…?
goes to the left (toward reactants).
When Q = K the reaction…?
is at equilibrium.
If the equilibrium constant is small, the reaction will not proceed very far to the right and therefore the initial reactant concentration is relatively _____ so we can assume that is ___ relative to the initial concentration.
large
small
What is Le Châtelier’s principle?
When a chemical system at equilibrium is disturbed, the system shifts in a direction that minimizes the disturbance.
Increasing the amount of one or more of the reactants (which makes Q < K) causes the reaction to shift to the ____ (in the direction of the _____)
right
products
Increasing the amount of one or more of the products (which makes Q > K) causes the reaction to shift to the ____ (in the direction of the ____)
left
reactants
Decreasing the amount of one or more of the reactants (which makes Q > K) causes the reaction to shift to the ____ (in the direction of the _____)
left
reactants
Decreasing the amount of one or more of the products (which makes Q < K) causes the reaction to shift to the ____ (in the direction of the _____)
right
products
Decreasing the volume causes the reaction to shift in the direction that has the _____ moles of gas particles.
fewer
Increasing the volume causes the reaction to shift in the direction that has the _____ moles of gas particles.
greater number
If a reaction has an equal number of moles of gas on both sides of the chemical equation, then a change in volume produces…?
no effect of the equilibrium
If you add an inert gas to a gas in a sealed container, does the equilibrium shift?
No because the partial pressure of the reactants and products do not change.
Increasing the temperature causes an exothermic reaction to shift ____ (in the direction of the ______); the value of the equilibrium constant _____
left
reactants
decreases
Decreasing the temperature causes an exothermic reaction to shift ____ (in the direction of the ______); the value of the equilibrium constant _____
right
products
increases
Increasing the temperature causes an endothermic reaction to shift ____ (in the direction of the ______); the value of the equilibrium constant _____
right
products
increases
Decreasing the temperature causes an endothermic reaction to shift ____ (in the direction of the ______); the value of the equilibrium constant _____
left
reactants
decreases
