General Chemistry Flashcards
Equilibrium of Reaction (26 cards)
What is chemical equilibrium?
Chemical equilibrium is the 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
Fill in the blank: The equilibrium constant (K) is a ratio of the concentrations of _____ to the concentrations of _____ at equilibrium.
products, reactants
What does a large equilibrium constant (K) indicate?
A large K indicates that the products are favored at equilibrium.
What does a small equilibrium constant (K) indicate?
A small K indicates that the reactants are favored at equilibrium.
What is Le Chatelier’s principle?
Le Chatelier’s principle states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system will adjust to counteract that change.
What happens to the position of equilibrium if the concentration of reactants is increased?
The position of equilibrium shifts to the right, favoring the formation of products.
What effect does increasing temperature have on an exothermic reaction at equilibrium?
Increasing temperature shifts the position of equilibrium to the left, favoring the reactants.
In the reaction A + B ⇌ C + D, what is the expression for the equilibrium constant (K)?
K = [C][D]/[A][B]
True or False: Catalysts affect the position of equilibrium.
False
What is the significance of the reaction quotient (Q)?
The reaction quotient (Q) compares the current concentrations of reactants and products to those at equilibrium.
If Q < K, which direction does the reaction shift?
The reaction shifts to the right, toward the products.
If Q > K, which direction does the reaction shift?
The reaction shifts to the left, toward the reactants.
What is the effect of decreasing the volume of a gaseous reaction at equilibrium?
Decreasing the volume shifts the equilibrium toward the side with fewer moles of gas.
Fill in the blank: The equilibrium constant is temperature _____ dependent.
dependent
What does a value of K equal to 1 indicate?
It indicates that neither reactants nor products are favored at equilibrium.
What is the standard condition for measuring equilibrium constants?
Standard conditions are typically 1 atm pressure and 25°C (298 K).
True or False: A system at equilibrium can still have reactants and products present.
True
What is the effect of adding an inert gas to a system at equilibrium?
Adding an inert gas at constant volume does not affect the position of equilibrium.
What is the difference between homogeneous and heterogeneous equilibrium?
Homogeneous equilibrium involves reactants and products in the same phase, while heterogeneous equilibrium involves reactants and products in different phases.
What is the role of temperature in the equilibrium constant expression?
Temperature affects the value of the equilibrium constant, as K changes with temperature.
What is the formula for the equilibrium constant expression for a reaction involving solids?
The concentrations of solids do not appear in the equilibrium constant expression.
What is meant by ‘dynamic equilibrium’?
Dynamic equilibrium refers to the continuous process of the forward and reverse reactions occurring at equal rates.
