AP Chemistry Flashcards: Properties of the Equilibrium Constant
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
The reaction A + B ⇌ C has K = 10. What is the equilibrium constant for the reaction 2C ⇌ 2A + 2B?
The reaction is reversed (1/K) and the coefficients are doubled (^2). The new K is (1/10)² = 1/100 or 0.01.
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The reaction A + B ⇌ C has K = 10. What is the equilibrium constant for the reaction 2C ⇌ 2A + 2B?
The reaction is reversed (1/K) and the coefficients are doubled (^2). The new K is (1/10)² = 1/100 or 0.01.
If the K for 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) is 25, what is the K for SO₃(g) ⇌ SO₂(g) + ½O₂(g)?
The reaction is reversed (1/K) and the coefficients are halved (^½). The new K is (1/25)^½ = 1/5 or 0.2.
How is the equilibrium constant for an overall reaction calculated when it is the sum of multiple individual reactions?
The equilibrium constant for the overall reaction is the product of the equilibrium constants of the individual reactions that were summed (K_overall = K₁ × K₂ × ...).
The reaction X ⇌ Y has an equilibrium constant K = 4. What is the K for the reaction 2X ⇌ 2Y?
Since the coefficients are multiplied by 2, the new K is the original K squared. K_new = 4² = 16.
When manipulating a reaction quotient (Q) for a reversed reaction, what operation is performed on the original Q value?
Just like with K, when a reaction is reversed, the new reaction quotient (Q_new) is the inverse of the original reaction quotient (Q_original).
If the reaction A ⇌ B has K = 5, what is the value of K for the reaction B ⇌ A?
The reaction is reversed, so the new K is the inverse of the original. K_new = 1/5 = 0.2.
Reaction 1 (K₁=2) and Reaction 2 (K₂=8) are added together. What is the equilibrium constant for the resulting overall reaction?
The overall K is the product of the individual K values. K_overall = K₁ × K₂ = 2 × 8 = 16.
What happens to the equilibrium constant (K) when a chemical reaction is reversed?
When a reaction is reversed, the new equilibrium constant becomes the inverse of the original equilibrium constant (K_new = 1/K_original).
Do the algebraic rules for manipulating the equilibrium constant (K) also apply to the reaction quotient (Q)?
Yes, all valid algebraic manipulations of K also apply to Q because the mathematical expressions for K and Q have identical forms.
What is the general principle for determining the equilibrium expression for a multistep process?
The overall equilibrium constant (K) for a multistep process is found by multiplying the K values for each individual reaction step that sums to the overall process.
How does multiplying the stoichiometric coefficients of a reaction by a factor 'c' affect its equilibrium constant, K?
When the coefficients of a reaction are multiplied by a factor 'c', the original equilibrium constant is raised to the power of 'c' (K_new = K_original^c).