Stoichiometry Helper

Solve stoichiometry problems step by step. Free online mole ratio and reaction calculator.

The Stoichiometry Helper guides you through mole-to-mole, mass-to-mass, and mass-to-mole conversions for chemical reactions. Enter the balanced equation coefficients and known quantities to find unknown amounts. This educational tool shows each step of stoichiometric calculations, making it perfect for learning and homework assistance.

Common use cases

  • Chemistry homework assistance
  • Reaction quantity predictions
  • Lab preparation calculations
  • Industrial process scaling
  • Understanding reaction proportions

How to use

  1. Enter coefficients from balanced equation
  2. Select known and unknown substances
  3. Enter the known quantity with units
  4. Click calculate for step-by-step solution
  5. View mole ratios and conversions

FAQ

What is stoichiometry?

The calculation of quantities in chemical reactions based on the balanced equation's mole ratios.

How do I use mole ratios?

The coefficients in a balanced equation give mole ratios. If 2A → 3B, then 2 moles of A produce 3 moles of B.

What is a limiting reagent?

The reactant that runs out first, determining the maximum product. Other reactants are in 'excess'.

How do I convert between mass and moles?

Moles = mass (g) / molar mass (g/mol). This connects measurable masses to stoichiometric mole ratios.