📘 Understanding Equilibrium Constant (Kc & Kp)

In chemistry, the equilibrium constant Calculator measures the ratio of product concentrations to reactant concentrations at equilibrium. It helps predict the position of equilibrium and the extent of a chemical reaction.

⚖️ Kc (Concentration-based)

The equilibrium constant in terms of concentration is:

Kc = [Products]^coeff / [Reactants]^coeff

Here, concentrations are expressed in molarity (mol/L).

🌡️ Kp (Pressure-based)

The equilibrium constant in terms of partial pressure is related to Kc by:

Kp = Kc × (RT)^Δn

Where Δn = (moles of gaseous products − moles of gaseous reactants), R = 0.082057 L·atm·K⁻¹·mol⁻¹, and T = temperature in Kelvin.

✅ Example

For the reaction: N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

• [N₂] = 0.2 M
• [H₂] = 0.3 M
• [NH₃] = 0.5 M

Kc = (0.5²) / (0.2 × 0.3³) = 46.3

Since Δn = (2 − 4) = −2, Kp can be calculated as Kp = Kc × (RT)⁻².

👉 Use the calculator above to easily compute Kc and Kp for any reaction!