⚗️ Stoichiometry Calculator
Perform stoichiometry calculations for any balanced chemical equation. Convert between moles, mass (grams), and particles (molecules/atoms) using the mole ratio from the balanced equation. Perfect for chemistry students, educators, and professionals.
What Is Stoichiometry?
Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. It's like the "recipe" of chemistry,it tells you how much of each ingredient (reactant) you need and how much product you'll get.
The foundation of all stoichiometry calculations is the balanced chemical equation. The coefficients in the balanced equation give you the mole ratio between any two substances in the reaction.
How the Calculator Works
This calculator performs stoichiometry calculations using these steps:
- Parse the Balanced Equation: Extracts coefficients for each compound.
- Convert Known Quantity to Moles: If mass is given, divides by molar mass. If particles are given, divides by Avogadro's number.
- Apply the Mole Ratio: Multiplies known moles by the ratio of target coefficient to known coefficient.
- Convert to Target Quantity: If target is mass, multiplies moles by molar mass. If target is particles, multiplies by Avogadro's number.
Key Formulas Used
Moles from Mass:
n = m / M
Moles from Particles:
n = N / NA
Mole Ratio:
ntarget = nknown × (coefftarget / coeffknown)
Mass from Moles:
m = n × M
Particles from Moles:
N = n × NA
Where: n = moles, m = mass (g), M = molar mass (g/mol), N = number of particles, NA = Avogadro's number (6.022 × 10²³)
Example Calculation
Problem: How many grams of H₂O form from 10.0 g of H₂ in the reaction 2 H₂ + O₂ → 2 H₂O?
Solution:
- Molar mass of H₂ = 2.016 g/mol
- Moles of H₂ = 10.0 g ÷ 2.016 g/mol = 4.960 mol
- Mole ratio H₂ : H₂O = 2 : 2 = 1 : 1
- Moles of H₂O = 4.960 mol × (2/2) = 4.960 mol
- Molar mass of H₂O = 18.015 g/mol
- Mass of H₂O = 4.960 mol × 18.015 g/mol = 89.4 g
Important Disclaimer
This calculator provides estimates for educational purposes only. Always verify your balanced equation and molar masses. Significant figures and experimental conditions may affect actual results. Consult a chemistry textbook or instructor for official guidance.
❓ Stoichiometry Calculator FAQ
What is stoichiometry?
Stoichiometry is the quantitative study of the relationships between reactants and products in chemical reactions. It uses balanced equations to determine how much of each substance is involved.
How do I use the stoichiometry calculator?
Enter a balanced chemical equation, select the known and target compounds, enter the known quantity value, and click "Calculate". The calculator will convert the known quantity to the target quantity using the mole ratio from the balanced equation.
What is the mole ratio?
The mole ratio is the ratio of coefficients of any two substances in a balanced chemical equation. It tells you how many moles of one substance react with or produce a certain number of moles of another.
What is Avogadro's number?
Avogadro's number is 6.022 × 10²³, the number of particles (atoms, molecules, or ions) in one mole of any substance.
How do I calculate molar mass?
Molar mass is the mass of one mole of a substance. It equals the sum of the atomic masses of all atoms in the chemical formula, expressed in grams per mole (g/mol).
What is the difference between moles and mass?
Moles measure the amount of substance (number of particles), while mass measures the weight of the substance. They are related by the molar mass: mass = moles × molar mass.
Can this calculator handle complex equations?
Yes, the calculator can handle equations with multiple reactants and products. Simply enter the balanced equation with coefficients and the calculator will extract the mole ratios.
What if my equation is not balanced?
The calculator requires a balanced equation to work correctly. Make sure all coefficients are in their lowest whole-number ratio and that mass is conserved on both sides of the equation.
How accurate are the results?
The calculator uses standard atomic weights and Avogadro's number. Results are accurate to the specified decimal precision. However, significant figures and experimental conditions may affect actual results.
Is this calculator free?
Yes, this calculator is completely free to use. No registration or personal data storage is required. All calculations are performed in your browser.