3.1.10.1 Gaseous Equilibria

• What are gaseous equilibria defined as?

  Reversible reactions in gases
• Steps to calculate Kp

  1️⃣ Determine the partial pressures of each gas at equilibrium

  2️⃣ Divide the product of partial pressures of the products by the product of partial pressures of the reactants

  3️⃣ Raise each partial pressure to the power of its stoichiometric coefficient
• Kp provides a quantitative measure of how far a reaction will proceed towards completion.


  True
• What is the Kp expression for the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?

  (P(NH₃)²) / (P(N₂) × P(H₂)³)
• The equilibrium constant Kp is the ratio of partial pressures of products to reactants
• The partial pressure of a gas is the pressure exerted by that individual gas in a mixture of gases
• The sum of all partial pressures in a gas mixture equals the total pressure of the system.


  True
• Match the term with its definition:

  Gaseous Equilibria ↔️ Reversible reactions with gases

  Kp ↔️ Ratio of partial pressures at equilibrium
• The partial pressure of a gas is the pressure exerted by a gas in a mixture of gases
• To apply Kp calculations, the first step is to determine the partial pressures of each gas at equilibrium.


  True
• When writing the Kp expression, the stoichiometric coefficients are used as exponents
• Match the term with its definition:

  Kp ↔️ Equilibrium constant using partial pressures

  Kc ↔️ Equilibrium constant using concentrations

  Δn ↔️ Change in moles of gas
• Steps to calculate Δn in the Kp-Kc relationship

  1️⃣ Count moles of gaseous products

  2️⃣ Count moles of gaseous reactants

  3️⃣ Subtract reactants from products
• For the reaction \(N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)\) at 298 K, if Kc = 0.5, the value of Kp is 0.00082
• Match the term with its definition:

  Gaseous Equilibria ↔️ Reversible reactions with all reactants and products in the gaseous phase

  Equilibrium Constant Kp ↔️ Ratio of partial pressures of products to reactants at equilibrium
• Gaseous equilibria involve reactions where all reactants and products are in the gaseous phase.


  True
• How is Kp calculated using partial pressures and stoichiometric coefficients?

  Divide products by reactants
• To write the Kp expression, the stoichiometric coefficients are used as exponents
• The equilibrium constant Kp provides a quantitative measure of how far a reaction will proceed towards completion.


  True
• What is the Kp expression for the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?

  $Kp =$$\frac{(P(NH_{3}))^{2}}{(P(N_{2}) \cdot (P(H_{2}))^{3})}$
• What is the pressure exerted by a gas in a mixture of gases called?

  Partial pressure
• For the reaction N2(g) + 3H2(g) ⇌ 2NH3(g), the Kp expression is $Kp =$$\frac{(P(NH_{3}))^{2}}{(P(N_{2}) \cdot (P(H_{2}))^{3})}$


  True
• What must be included when calculating Kp?

  Correct units
• What is the value of the ideal gas constant R in L atm / (mol K)?

  0.0821
• What are the units of Kp?

  atm⁻¹
• Match the reaction with its Kp value:

  \(N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)\) ↔️ 0.593

  \(PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)\) ↔️ 3.2

  \(2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)\) ↔️ 8.0
• The equilibrium constant Kp is the ratio of partial pressures of products to reactants at equilibrium
• Partial pressure is the pressure exerted by an individual gas in a mixture of gases
• What does the equilibrium constant Kp measure in gaseous equilibria?

  Ratio of partial pressures
• Steps to calculate Kp

  1️⃣ Determine partial pressures of each gas at equilibrium

  2️⃣ Write the Kp expression using stoichiometric coefficients

  3️⃣ Substitute partial pressures into the Kp expression

  4️⃣ Calculate Kp and include units
• What do P(NH₃), P(N₂), and P(H₂) represent in the Kp expression for the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?

  Partial pressures at equilibrium
• What are the units of Kp for the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?

  atm⁻²
• Steps to calculate Kp

  1️⃣ Determine the partial pressures of each gas at equilibrium

  2️⃣ Divide the product of partial pressures of products by reactants

  3️⃣ Raise each partial pressure to its stoichiometric coefficient
• The Kp expression is defined as the ratio of partial pressures of products to reactants, raised to their stoichiometric coefficients
• The equilibrium constant based on partial pressures is denoted by Kp
• What is the first step in applying Kp calculations to gaseous homogeneous systems?

  Determine partial pressures
• Kp uses partial pressures, while Kc uses concentrations

  True
• The temperature in the Kp-Kc relationship must be in Kelvin
• The ideal gas constant R has units of L atm / (mol K)


  True