Relationship Between Equilibrium Constants

Overview

The relationship between equilibrium constants is defined by the fact that the expressions for equilibrium constants depend on the concentration units used, typically expressed in moles per cubic decimeter ( mol dm-3 ). For a reversible reaction represented as

aA + bB ⇌ cC + dD
the equilibrium constant (K) is calculated as K = [C]c[D]d / [A]a[B]b, where the coefficients of the balanced equation appear as exponents in the expression. The value of the equilibrium constant is specific to a particular reaction and remains constant at a given temperature, providing insights into the direction and extent of the reaction

Questions and Answers

  1. How does the equilibrium constant relate to the concentrations of reactants and products?

    The equilibrium constant is the ratio of the products of the concentrations of the products to the products of the concentrations of the reactants at equilibrium

  2. What happens to the value of the equilibrium constant if the temperature changes?

    The value of the equilibrium constant is specific to a particular reaction and remains constant at a given temperature; it changes if the temperature is altered

  3. What does a large equilibrium constant indicate about a reaction?

    A large equilibrium constant indicates that the reaction is almost complete, favoring the formation of products

  4. What is the significance of the coefficients in the equilibrium constant expression?

    The coefficients in the balanced equation appear as exponents in the equilibrium constant expression, reflecting the stoichiometry of the reaction

  5. How do changes in concentration affect the position of equilibrium?

    Changes in concentration can shift the position of equilibrium, but they do not alter the value of the equilibrium constant itself

Multiple-Choice Questions

  1. What does a large equilibrium constant (K) indicate about a reaction?

    a) The reaction is incomplete
    b) The reaction favors the reactants
    c) The reaction is almost complete
    d) The reaction does not occur
    Answer: c) The reaction is almost complete

  2. Which of the following statements is true regarding the equilibrium constant?

    a) It changes with concentration
    b) It is specific to a particular reaction at a given temperature
    c) It is always equal to 1
    d) It is dependent on the pressure only
    Answer: b) It is specific to a particular reaction at a given temperature

  3. What is the relationship between Kc and Kp for reactions involving gases?

    a) Kc is always greater than Kp
    b) Kp is always greater than Kc for reactions with an increase in moles
    c) Kc and Kp are always equal
    d) Kp is independent of temperature
    Answer: b) Kp is always greater than Kc for reactions with an increase in moles

  4. What effect does increasing the concentration of reactants have on the equilibrium position?

    a) It shifts the equilibrium to the left
    b) It shifts the equilibrium to the right
    c) It has no effect on the equilibrium position
    d) It decreases the value of K
    Answer: b) It shifts the equilibrium to the right

  5. Which of the following is true about the equilibrium constant K?

    a) It has units that are always the same
    b) It can be calculated using the concentrations of reactants only
    c) It is a ratio of the concentrations of products to reactants
    d) It is affected by the presence of a catalyst
    Answer: c) It is a ratio of the concentrations of products to reactants