Reaction Quotient Calculator

Reaction Quotient Calculator

Calculate Q for any chemical reaction

Result

Reaction Quotient Calculator

This calculator helps you determine the reaction quotient (Q) for a chemical reaction at any point in time. The reaction quotient is a measure of the relative amounts of products and reactants present during a reaction at a particular point in time.

How to Use This Calculator

  1. Enter the number of reactants and products in your chemical equation
  2. For each reactant and product, enter its concentration (in molarity, M)
  3. Enter the stoichiometric coefficient for each species (the number before each compound in the balanced equation)
  4. Click "Calculate Reaction Quotient" to get the Q value

Formula

The reaction quotient Q is calculated using the formula:

Q = [C]ᶜ[D]ᵈ / [A]ᵃ[B]ᵇ

Where:

  • A, B are reactants
  • C, D are products
  • a, b are stoichiometric coefficients of reactants
  • c, d are stoichiometric coefficients of products
  • [] represents concentrations (in Molarity, M)

Example Calculation

For the reaction: 2A + B ⇌ 3C + D

With concentrations: [A] = 0.5 M, [B] = 0.2 M, [C] = 0.1 M, [D] = 0.4 M

Q = [C]³[D] / [A]²[B] = (0.1)³(0.4) / (0.5)²(0.2) = 0.0004 / 0.05 = 0.008

Interpreting the Result

  • If Q < K (equilibrium constant): The reaction will proceed forward to produce more products
  • If Q = K: The reaction is at equilibrium
  • If Q > K: The reaction will proceed in reverse to produce more reactants