Equilibrium Constant Calculator
Works out Kc for a reaction with up to two reactants and two products.
Equilibrium constant Kc
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Products term, [C]^c [D]^d —
Reactants term, [A]^a [B]^b —
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The formula
K = [C]^c [D]^d ÷ ([A]^a [B]^b)
Products over reactants, each raised to its coefficient. A large K means the equilibrium lies towards the products.
What to watch out for
The default values are H₂ + I₂ ⇌ 2HI, with D left out by a coefficient of 0.
Frequently Asked Questions
What is K for H₂ + I₂ ⇌ 2HI with 0.02, 0.02 and 0.16 mol/L?
0.16² ÷ (0.02 × 0.02) = 64.
Why are solids and pure liquids left out?
Their concentration does not change during the reaction, so they are built into the constant.