Equilibrium Constant Calculator (Kc) - Calculate Chemical Equilibrium
The equilibrium constant (Kc) is a value that expresses the ratio of product concentrations to reactant concentrations at equilibrium. For a reaction aA + bB ⇌ cC + dD, the equilibrium constant is Kc = [C]^c[D]^d / [A]^a[B]^b. The Kc value indicates the reaction tendency: Kc > 1 means more products (reaction shifts to the right), Kc < 1 means more reactants (reaction shifts to the left), and Kc = 1 means products and reactants are balanced.
Kc = [Products]^n / [Reactants]^mVariables:
- KcEquilibrium constant(e.g.: 2.5)
- [Products]Product concentration(e.g.: 0.5 M)
- [Reactants]Reactant concentration(e.g.: 0.2 M)
- n, mStoichiometric coefficient(e.g.: 2, 1)
Categories:
How to Use the Calculator
- 1
Enter Concentrations
Enter product and reactant concentrations in molar (M).
- 2
Enter Coefficients
Enter stoichiometric coefficients from the balanced equation.
- 3
Calculate
Click calculate to get the Kc value.
Examples
Simple Reaction
Problem:
For reaction A + B ⇌ C with [C]=0.8 M, [A]=0.4 M, [B]=0.4 M. Calculate Kc!
Solution:
- 1.Kc = [C] / ([A][B])
- 2.Kc = 0.8 / (0.4 × 0.4)
- 3.Kc = 0.8 / 0.16 = 5
Result:5
Kc = 5, indicating the reaction favors product formation.
Frequently Asked Questions
What does the Kc value mean?
Kc > 1 means more products; Kc < 1 means more reactants; Kc = 1 means equilibrium. The larger Kc, the more product is formed.
What affects the Kc value?
Kc is affected only by TEMPERATURE. Changes in concentration, pressure, or catalyst do NOT change Kc—they only shift the equilibrium position.