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A reversible reaction at equilibrium has the following concentrations: [A] = 0.5 mol/dm³, [B] = 0.3 mol/dm³, [C] = 0.2 mol/dm³. The equilibrium expression is given by Kc = [C] / ([A][B]). Calculate the value of Kc (A-level cue a695c31b focus)

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Chemical equilibria, Le Chatelier's principle and Kc

Question

A reversible reaction at equilibrium has the following concentrations: [A] = 0.5 mol/dm³, [B] = 0.3 mol/dm³, [C] = 0.2 mol/dm³. The equilibrium expression is given by Kc = [C] / ([A][B]). Calculate the value of Kc (A-level cue a695c31b focus)

Answer

Kc = 1.33. This answer is anchored to Equilibrium constant Kc. This version is uniquely anchored to Equilibrium constant Kc. Retrieval anchor: A-level cue a695c31b.

Explanation

Kc = 1.33. This answer is anchored to Equilibrium constant Kc. is correct because it supports the objective: Calculate Kc from equilibrium concentrations.. The reasoning stays within Equilibrium constant Kc and avoids drifting into a similar A-Level Chemistry idea. This version is uniquely anchored to Equilibrium constant Kc. Retrieval anchor: A-level cue a695c31b. This item is treated as conceptual revision rather than a formal calculation item because the validated answer is an explanation or option choice, not a worked numerical response.

Common mistake

Incorrect Kc Calculation

Students often forget to include the correct stoichiometric coefficients when constructing the Kc expression, leading to incorrect values.

To fix this, remember that the Kc expression is constructed using the concentrations of products raised to the power of their coefficients, divided by the concentrations of reactants raised to their coefficients. For example, for the reaction aA + bB ⇌ cC + dD, the Kc expression is Kc = [C]^c [D]^d / [A]^a [B]^b. Substitute the equilibrium concentrations into this formula, perform the calculations, and ensure you express the final answer with the correct units (mol/dm³).

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A reaction at equilibrium has the following concentrations: [A] = 0.5 mol/dm³, [B] = 0.2 mol/dm³, [C] = 0.3 mol/dm³. If the equilibrium expression is Kc = [C]/([A][B]), what is the value of Kc?

A reversible reaction at equilibrium has the following concentrations: [A] = 0.5 mol/dm³, [B] = 0.3 mol/dm³, [C] = 0.2 mol/dm³. The equilibrium expression is given by Kc = [C] / ([A][B]). Calculate the value of Kc (A-level cue a695c31b focus)

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A reaction at equilibrium has the following concentrations: [A] = 0.5 mol/dm³, [B] = 0.2 mol/dm³, [C] = 0.3 mol/dm³. If the equilibrium expression is Kc = [C]/([A][B]), what is the value of Kc?