For each of the equilibria in Problem 15.56, write the equi-librium constant expression for Kp and give the equation that relates Kp and Kc. (a)

Verified step by step guidance

1. Identify the chemical equilibrium reaction for which you need to write the equilibrium constant expression.
2. Recall that the equilibrium constant expression for Kp is written in terms of the partial pressures of the gases involved in the reaction.
3. Write the expression for Kp by taking the product of the partial pressures of the products, each raised to the power of their stoichiometric coefficients, and dividing by the product of the partial pressures of the reactants, each raised to the power of their stoichiometric coefficients.
4. Use the equation that relates Kp and Kc: \( K_p = K_c (RT)^{\Delta n} \), where \( R \) is the ideal gas constant, \( T \) is the temperature in Kelvin, and \( \Delta n \) is the change in moles of gas (moles of gaseous products minus moles of gaseous reactants).
5. Substitute the appropriate values into the equation to relate Kp and Kc, ensuring you have the correct \( \Delta n \) for the reaction.

Key Concepts

Equilibrium Constant (Kp)

The equilibrium constant Kp is a numerical value that expresses the ratio of the partial pressures of the products to the reactants at equilibrium for a gaseous reaction. It is derived from the balanced chemical equation and is specific to a given temperature. Kp is particularly useful for reactions involving gases, as it directly relates to their partial pressures.

Equilibrium Constant (Kc)

Kc is the equilibrium constant that expresses the ratio of the concentrations of products to reactants at equilibrium for a reaction in solution. It is calculated using molarity (moles per liter) and is also temperature-dependent. Kc is applicable to reactions involving aqueous solutions and is essential for understanding how concentration changes affect equilibrium.

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 for the conversion between the two constants, depending on whether the reaction is analyzed in terms of partial pressures or concentrations.