How to use the equilibrium constant from rate constants calculator
Find the equilibrium constant and standard free energy change from forward and reverse rate constants. Enter forward rate constant, reverse rate constant, temperature in the fields above; the equilibrium constant k, standard free energy change are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “K = kf over kr”, “equilibrium from rate constants”, “free energy from rates”, “calculate equilibrium constant from rate constants”, “find equilibrium constant k”.
Formula
Variables
- kf — Forward rate constant (s⁻¹)
- kr — Reverse rate constant (s⁻¹)
- T — Temperature (K)
Worked example
With forward rate constant = 0.5 s⁻¹, reverse rate constant = 0.02 s⁻¹, temperature = 298.15 K, the calculator gives equilibrium constant k ≈ 25; standard free energy change ≈ -7.979455 kJ/mol.
Frequently asked questions
What is the equilibrium constant from rate constants calculator used for?
Find the equilibrium constant and standard free energy change from forward and reverse rate constants. It helps with questions such as “K = kf over kr”, “equilibrium from rate constants”, “free energy from rates”.
What is the formula for the equilibrium constant from rate constants calculation?
Equilibrium constant K = kf / kr. Standard free energy change (kJ/mol) = -RGAS × T × ln(kf / kr) / 1000. Here kf is forward rate constant (s⁻¹), kr is reverse rate constant (s⁻¹), T is temperature (K).
What inputs do I need for the equilibrium constant from rate constants calculator?
You need forward rate constant in s⁻¹, reverse rate constant in s⁻¹, temperature in K. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the equilibrium constant from rate constants calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the equilibrium constant from rate constants result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.