LO 36 - 41 Flashcards
Pure solids are ________ in the equilibrium expression because their __________ is incorporated into the value K
NOT included
constant value
What are the steps associated with using a RICE table?
- write the balanced reaction (R)
- report the initial (I) concentrations
- use the stoichiometric values from the balanced equation to determine change (C)
- sum columns OR solve for x change to determine concentrations at equilibrium (E)
Pure liquids are ________ in the equilibrium expression because their __________ is incorporated into the value K
NOT included
constant value
The _______ is used to predict direction of reaction change relative to equilibrium.
reaction quotient (Q)
How is the reaction quotient (Q) different from the equilibrium constant (K)
at a given temperature, K only has one value with specified ratios at equilibrium whereas Q depends on the concentrations at the current reaction state
Q approaches 0 = _______
Q approaches ∞ = _______
Q equals 1 = _______
only reactants are present
only products are present
both reactants and products at 1M
Q relative to K measures progress of a reaction towards equilibrium where _______
Q = K
Rule of thumb when comparing Q and K
“From Q to K, go the alligator’s way”
Q < K
reaction goes right towards products
Q > K
reaction goes left towards reactants
Q = K
reaction is at equilibrium
Given an unknown change in concentration while using a RICE table, what are the two methods to solve?
- quadratic formula
- approximation when K value is small
How do you check an approximation when solving a RICE table?
Check that the calculated x value is less than 5% of the initial concentration value being subtracted from
Le Chatelier’s Principle
when a system is disturbed, the system shifts in a direction that minimizes the distrurbance
Increasing the concentration of one or more reactants (Q < K) causes the reaction to shift _________
right towards products
Increasing the concentration of one or more products (Q > K) causes the reaction to shift _________
left towards reactants
Decreasing the concentration of one or more reactants (Q > K) causes the reaction to shift _______
left towards reactants
Decreasing the concentration of one or more products (Q < K) causes the reaction to shift _______
right towards products
Decreasing the volume of a gaseous reaction causes the reaction to shift in the direction that has . . .
fewer mols of gas particles
Increasing the volume of a gaseous reaction causes the reaction to shift in the direction that has . . .
greater mols of gas particles
Adding an inert gas to a gaseous reaction at a fixed volume . . .
does nothing
When a reaction has an equal number gaseous mols on both sides of the equation, a change in volume will produce . . .
no change
Changes in volume or concentration change ___ while changes in temperature effect ____
Q
K
Exothermic reactions have heat as a _____
product (heat OUT)
Increasing the temperature causes an exothermic reaction to shift . . .
left towards reactants (K decreases)
Decreasing the temperature causes an exothermic reaction to shift . . .
right towards products (K increases)
Endothermic reactions have heat as a _______
reactant (heat IN)
Increasing the temperature causes an endothermic reaction to shift . . .
right towards products (K increases)
Decreasing the temperature causes an endothermic reaction to shift . . .
left towards reactants (K decreases)
