For each of the equilibria in Problem 15.57, write the equilibrium constant expression for Kp and give the equation that relates Kp and Kc for parts (a), (b), and (c).

Name: Chemistry
Author: McMurry
ISBN: 9781292336145

검증된 단계별 안내

Step 1: Identify the chemical equilibrium reactions given in Problem 15.57. Each reaction will have a specific form, such as aA(g) + bB(g) ⇌ cC(g) + dD(g).

Step 2: Write the equilibrium constant expression for Kp for each reaction. Kp is expressed in terms of the partial pressures of the gases involved: Kp = (P_C^c * P_D^d) / (P_A^a * P_B^b), where P represents the partial pressure of each gas.

Step 3: Recall the relationship between Kp and Kc. The equation that relates Kp and Kc is: Kp = Kc(RT)^Δn, where R is the ideal gas constant (0.0821 L·atm/mol·K), T is the temperature in Kelvin, and Δn is the change in moles of gas (moles of gaseous products - moles of gaseous reactants).

Step 4: For each reaction, calculate Δn by subtracting the sum of the coefficients of the gaseous reactants from the sum of the coefficients of the gaseous products.

Step 5: Use the relationship Kp = Kc(RT)^Δn to express Kp in terms of Kc for each reaction, substituting the appropriate values for R, T, and Δn.

주요 개념

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Equilibrium Constant (Kp and Kc)

The equilibrium constant (K) quantifies the ratio of the concentrations of products to reactants at equilibrium. Kp is used for gas-phase reactions and is expressed in terms of partial pressures, while Kc is used for reactions in solution and is expressed in terms of molar concentrations. The relationship between Kp and Kc is crucial for converting between these two forms, especially when dealing with gaseous reactions.

Relationship between Kp and Kc

The relationship between Kp and Kc is given by the equation Kp = Kc(RT)^(Δn), where R is the ideal gas constant, T is the temperature in Kelvin, and Δn is the change in the number of moles of gas (moles of products minus moles of reactants). This equation allows chemists to convert between the two constants depending on the conditions of the reaction, particularly when dealing with gaseous reactants and products.

Equilibrium Expressions

Equilibrium expressions are mathematical representations of the concentrations or partial pressures of reactants and products at equilibrium. For a general reaction aA + bB ⇌ cC + dD, the equilibrium expression is written as K = [C]^c[D]^d / [A]^a[B]^b for Kc, and similarly for Kp using partial pressures. Understanding how to construct these expressions is essential for calculating equilibrium constants and analyzing chemical equilibria.