Chemistry - 1.6 - Chemical Equilibria Flashcards
(31 cards)
What is chemical equilibrium?
A state in a reversible reaction where the rates of the forward and reverse reactions are equal.
True or False: At equilibrium, the concentrations of reactants and products remain constant.
True
What is the equilibrium constant (Kc) expression for the reaction aA + bB ⇌ cC + dD?
Kc = [C]^c [D]^d / [A]^a [B]^b
What does a large Kc value indicate about a reaction at equilibrium?
It indicates that the products are favored over the reactants.
Fill in the blank: The position of equilibrium can be changed by altering __________.
concentration, pressure, or temperature
What is Le Chatelier’s Principle?
If a dynamic equilibrium is disturbed, the position of equilibrium shifts to counteract the change.
How does increasing the concentration of reactants affect the position of equilibrium?
It shifts the equilibrium position to the right, favoring the formation of products.
True or False: A catalyst affects the position of equilibrium.
False
What happens to the equilibrium position when the temperature of an exothermic reaction is increased?
The equilibrium shifts to the left, favoring the reactants.
What is the effect of increasing pressure on a gaseous equilibrium with more moles of reactants than products?
The equilibrium shifts to the left, favoring the reactants.
Define dynamic equilibrium.
A condition where the forward and reverse reactions occur at the same rate, resulting in no net change in concentration.
What is the significance of the equilibrium constant Kp?
It expresses the equilibrium position of a reaction involving gases in terms of partial pressures.
How can you calculate Kp from Kc?
Kp = Kc(RT)^(Δn), where Δn is the change in moles of gas.
What does it mean if Kc is equal to 1?
It indicates that both reactants and products are present in significant amounts at equilibrium.
Fill in the blank: An increase in temperature favors the endothermic direction of a reversible reaction, shifting the equilibrium to the __________.
right (products)
What type of reaction is favored if the equilibrium constant Kc is less than 1?
The reactants are favored.
True or False: The units of Kc depend on the stoichiometry of the reaction.
True
What does the term ‘homogeneous equilibrium’ refer to?
An equilibrium system where all reactants and products are in the same phase.
What is the difference between homogeneous and heterogeneous equilibrium?
Homogeneous equilibrium involves reactants and products in the same phase, while heterogeneous involves different phases.
Fill in the blank: In a reaction where the number of moles of gas decreases, increasing pressure will shift the equilibrium to the __________.
right (products)
What is the relationship between Kc and temperature?
Kc varies with temperature; different temperatures will yield different equilibrium constants.
What is meant by the term ‘reaction quotient’ (Q)?
Q is the ratio of product concentrations to reactant concentrations at any point in time, not necessarily at equilibrium.
How can you determine the direction of shift for a reaction at equilibrium if Q does not equal K?
If Q < K, the reaction shifts to the right; if Q > K, it shifts to the left.
What effect does adding an inert gas at constant volume have on the equilibrium position?
It has no effect on the equilibrium position.
