7.3 Calculating Equilibrium Concentrations

• The equilibrium constant (K) determines the relative amounts of reactants and products at equilibrium.


  True
• Kp is used for reactions involving gases
• If Kc > 1, the equilibrium favors the products.


  True
• Determine the change in concentrations based on the stoichiometry of the reaction
• Solve for x using the quadratic formula.
• The quadratic equation is used to find the roots of a second-degree polynomial equation.


  True
• Initial concentrations refer to the starting amounts of reactants and products before the system reaches equilibrium
• What is the formula for Kc?

  [Products] / [Reactants]
• Steps for using the ICE table method:

  1️⃣ Write the balanced chemical equation

  2️⃣ Set up the ICE table

  3️⃣ Fill in initial concentrations

  4️⃣ Determine the change in concentrations

  5️⃣ Express equilibrium concentrations
• The equilibrium expression for the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g) is K = [NH₃]² / ([N₂][H₂]³)


  True
• What is the approximate value of x when solving for equilibrium concentrations in the reaction H₂(g) + I₂(g) ⇌ 2HI(g)?

  0.85
• What does a value of K > 1 indicate about the equilibrium position?

  Products are favored
• What do equilibrium constants represent numerically?

  Ratio of product to reactants
• What is equilibrium concentration in a chemical system?

  Constant concentrations at equilibrium
• What does Kc refer to in equilibrium calculations?

  Concentration equilibrium constant
• Match the equilibrium constant with its definition:

  Kc ↔️ Molar concentrations at equilibrium

  Kp ↔️ Partial pressures at equilibrium
• What does the ICE table method help organize in equilibrium calculations?

  Concentrations of reactants and products
• What is the value of x when solving for equilibrium concentrations in the example reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?

  0.5
• What is the equilibrium expression for the reaction H₂(g) + I₂(g) ⇌ 2HI(g)?

  K = [HI]² / ([H₂][I₂])
• The equilibrium constant K determines the relative amounts of reactants and products at equilibrium.
• Kc is expressed using molar concentrations while Kp uses partial pressures.
• The equilibrium constant Kc applies to reactions in solution
• The formula for Kp is (Partial Pressure of Products) / (Partial Pressure of Reactants
• What is the first step in solving equilibrium concentration problems using the quadratic equation?

  Set up the ICE table
• What value of x is used in the final equilibrium concentration calculations?

  Positive root
• What does the ICE table organize in equilibrium problems?

  Initial, Change, Equilibrium
• Only the positive root of the quadratic formula is used in equilibrium problems because concentrations cannot be negative.


  True
• The value of x for the reaction H₂(g) + I₂(g) ⇌ 2HI(g) is approximately 0.85.


  True
• Match the equilibrium constant with its application:

  Kc ↔️ Reactions in solution

  Kp ↔️ Reactions involving gases
• What is the primary application of the Kp equilibrium constant?

  Reactions involving gases
• The ICE table is used to set up the equilibrium expression
• Match the factor with its effect on equilibrium concentrations:

  Equilibrium Constant (K) ↔️ Determines the relative concentrations of reactants and products

  Initial Concentrations ↔️ Affects the absolute concentrations of reactants and products
• The formula for Kp is (Partial Pressure of Products) / (Partial Pressure of Reactants).

  True
• The formula for Kc is [Reactants] / [Products].

  False
• A Kp value greater than 1 indicates that reactants are favored at equilibrium.

  False
• The equilibrium expression is formulated using the equilibrium concentrations from the ICE table.


  True
• Only positive roots of the quadratic equation are physically meaningful for equilibrium calculations.


  True
• Steps to solve equilibrium concentration problems using the quadratic equation

  1️⃣ Set up the ICE table

  2️⃣ Formulate the equilibrium expression

  3️⃣ Substitute equilibrium concentrations

  4️⃣ Solve for x using the quadratic formula

  5️⃣ Determine the positive root

  6️⃣ Calculate the final equilibrium concentrations
• What is the equilibrium constant for the reaction H₂(g) + I₂(g) ⇌ 2HI(g)?

  K = 50
• The final equilibrium concentration of H₂ for the reaction H₂(g) + I₂(g) ⇌ 2HI(g) is 0.15 M