Textbook Question
At 1000 K, πΎπ = 1.85 for the reaction SO2(π) + 12 O2(π) β SO3(π) (c) What is the value of πΎπ for the reaction in part (b)?
Ch.15 - Chemical Equilibrium
Chapter 15, Problem 28
Consider the equilibrium N2(π) + O2(π) + Br2(π) β 2 NOBr(π) Calculate the equilibrium constant πΎπ for this reaction, given the following information at 298 K:
2 NO(π) + Br2(π) β 2 NOBr(π) πΎπ = 2.02
NO(π) β N2(π) + O2(π) πΎπ = 2.1Γ1030
Verified step by step guidance1
Identify the given reactions and their equilibrium constants. The first reaction is 2 NO(g) + Br2(g) β 2 NOBr(g) with Kc = 2.02. The second reaction is NO(g) β N2(g) + O2(g) with Kc = 2.1Γ10^30.
Write the target reaction in terms of the given reactions. The target reaction is N2(g) + O2(g) + Br2(g) β 2 NOBr(g). Notice that this can be achieved by reversing the second reaction and then adding it to the first reaction.
Calculate the equilibrium constant for the reversed second reaction. For a reaction that is reversed, the equilibrium constant is the reciprocal of the original. Thus, Kc for the reversed reaction N2(g) + O2(g) β NO(g) is 1/(2.1Γ10^30).
Combine the equilibrium constants of the adjusted reactions to find the equilibrium constant for the target reaction. When reactions are added, their equilibrium constants are multiplied. Therefore, multiply the Kc of the reversed second reaction with the Kc of the first reaction.
Convert the combined Kc to Kp using the relation Kp = Kc(RT)^(Ξn), where Ξn is the change in moles of gas between reactants and products, R is the gas constant, and T is the temperature in Kelvin. Calculate Ξn for the target reaction and use it to find Kp.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Equilibrium Constant (K)
The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given chemical reaction. It is specific to a particular reaction at a certain temperature. For reactions involving gases, the equilibrium constant can be expressed in terms of partial pressures (Kp) or concentrations (Kc), depending on the state of the reactants and products.
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01:14
Equilibrium Constant K
Relationship Between Kp and Kc
The relationship between Kp and Kc is defined by the equation Kp = Kc(RT)^(Ξn), where R is the ideal gas constant, T is the temperature in Kelvin, and Ξn is the change in the number of moles of gas between products and reactants. This relationship allows for the conversion of equilibrium constants from concentration-based to pressure-based values, which is essential when dealing with gaseous reactions.
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02:18Kp vs Kc Relationship
Le Chatelier's Principle
Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system will adjust itself to counteract the change and restore a new equilibrium. This principle is crucial for understanding how changes in concentration, pressure, or temperature affect the position of equilibrium and the values of Kp and Kc in a chemical reaction.
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07:32Le Chatelier's Principle
Related Practice
Textbook Question
Consider the following equilibrium, for which at πΎπ = 0.0752 at 480Β°C: 2 Cl2(π) + 2 H2O(π) β 4 HCl(π) + O2(π) (a) What is the value of πΎπ for the reaction 4 HCl(π) + O2(π) β 2 Cl2(π) + 2 H2O(π)?
Textbook Question
The following equilibria were attained at 823 K:
CoO(s) + H2(g) β Co(s) + H2O(g) Kc = 67
CoO(s) + CO(g) β Co(s) + CO2(g) Kc = 490
Based on these equilibria, calculate the value of πΎπ for H2(π)+ CO2(π) β CO(π) + H2O(π) at 823 K.