Le Chatelier's Principle Calculator

Apply Le Chatelier's principle to predict equilibrium shifts. Calculate new equilibrium position after changes to concentration, temperature, or pressure for any reversible reaction.

⚖️ Equilibrium📐 Le Châtelier: System resists stress🧪 Chemistry
Equilibrium constant K
Current [products]^n
Current [reactants]^n
Please enter valid values.

Formula & Reference

VariableSymbolFormulaUnits
Le Chatelier's Principle CalculatorSee formulaLe Châtelier: System resists stressshift direction

Step-by-Step Examples

Example 1
Add Reactant

K=2.96. At equilibrium: [NH3]^2=0.0400, [N2][H2]^3=0.0135. Add N2: Q becomes smaller.

  • Original Q = 0.0400/0.0135 = 2.96 = K (at equilibrium)
  • After adding N2: denominator increases, Q < K
  • Equilibrium shifts forward, making more NH3
✓ Adding reactant shifts equilibrium forward
Example 2
Increase Temperature (Exothermic)

N2+3H2 to 2NH3 is exothermic (dH < 0). Raise T.

  • Treat heat as a product for exothermic reaction
  • Adding heat (product) shifts reaction REVERSE
  • K decreases when T increases for exothermic reactions
✓ K decreases; less NH3 at higher T
Example 3
Add Inert Gas

Inert gas added to gas mixture at constant volume.

  • Partial pressures of reactants and products unchanged
  • Q unchanged, no shift in equilibrium
  • Inert gas at constant volume has no effect on equilibrium
✓ No shift: inert gas at constant volume has no effect

Real-World Applications

🏭
Industrial Optimization
Haber process: 200 atm, 450-500 C, Fe catalyst. Compromise between yield (low T favors) and rate (high T needed).
🌍
Ocean Acidification
CO2 + H2O to H2CO3 equilibrium shifts right as atmospheric CO2 increases.
🧪
Reaction Design
Chemists use Le Chatelier to maximize product yield by removing products as formed.
💧
Solubility Control
Adding acid to dissolve carbonates: H+ reacts with CO3^2-, shifting dissolution equilibrium right.

Common Mistakes to Avoid

⚠️
Q vs K predicts shift direction

Calculate Q from current concentrations. If Q < K: shift forward. If Q > K: shift reverse. If Q = K: no shift.

⚠️
Increasing T for endothermic reactions

For endothermic (dH > 0): higher T increases K (more products). For exothermic: higher T decreases K (fewer products).

⚠️
Pressure effects only for gases

Increasing pressure shifts toward side with fewer moles of GAS. Liquids and solids are unaffected by pressure changes.

Frequently Asked Questions

What is Le Chatelier's Principle? ▾
A system at equilibrium, when stressed (concentration, T, P change), shifts to partially counteract the stress and reach a new equilibrium.
Does a catalyst shift equilibrium? ▾
No. A catalyst increases the RATE of both forward and reverse reactions equally. Equilibrium position (K) is unchanged.
How does removing product affect equilibrium? ▾
Removing product decreases [products], so Q < K. Equilibrium shifts forward to make more product. Used in synthesis to drive reaction to completion.
What is the effect of volume change? ▾
Decreasing volume (increasing P): shifts toward fewer moles of gas. Increasing volume: shifts toward more moles of gas.
Why does increasing T decrease K for exothermic reactions? ▾
At higher T, the extra kinetic energy helps break product bonds back to reactants. Mathematically: d(lnK)/dT = dH/(RT^2). If dH < 0, d(lnK)/dT < 0.

Related Chemistry Calculators

⚖️ Equilibrium Constant⚖️ Reaction Quotient Q⚡ Gibbs Free Energy⚗️ Kp to Kc💧 Ksp Calculator

Formula Explorer connections

Interpretation: This formula describes how reactants, products, ions or phases distribute when opposing processes reach equilibrium. Assumption: Use equilibrium rather than initial concentrations, correct stoichiometric exponents, and the specified temperature; activities may replace concentrations in nonideal systems.

Le Chatelier Principle Calculator →Radioactive Equilibrium Calculator →Reaction Quotient Calculator →Chemistry Formula Explorer →