Stoichiometry Calculator

Calculate the amount of product or reactant using mole ratios.

Stoichiometry Calculator

Calculate the amount of product or reactant using mole ratios.

Formula
moles of B = moles of A x (coefficient B / coefficient A)
What is This Tool?

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in a balanced chemical equation. By using mole ratios from the balanced equation, you can predict how much product forms or how much reactant is needed.

Formula
moles of B = moles of A x (coefficient of B / coefficient of A) The coefficients come from the balanced chemical equation.
Worked Examples

1. Combustion of methane

Given: CH4 + 2O2 -> CO2 + 2H2O; 3 mol CH4

Mole ratio of H2O to CH4 = 2/1

Moles H2O = 3 x (2/1) = 6 mol

Result: 6 mol H2O produced

2. Synthesis of ammonia

Given: N2 + 3H2 -> 2NH3; 5 mol H2

Mole ratio of NH3 to H2 = 2/3

Moles NH3 = 5 x (2/3) = 3.33 mol

Result: 3.33 mol NH3 produced

Frequently Asked Questions