Stoichiometry Converter

Convert between moles, grams, and molecules in chemical reactions

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Quick Presets

Convert Between Moles, Grams, and Molecules

Compound:

Molar Mass:

18.015 g/mol

Amount:

Unit:

Conversion Results:

Molar Mass: 18.015 g/mol

Moles:

1.000 mol

Mass:

18.02 g

Molecules:

6.0221e+23

Understanding Stoichiometry

Stoichiometry is the calculation of relative quantities of reactants and products in chemical reactions. It's based on the law of conservation of mass and the law of constant proportions.

Key Concepts:

Mole: The SI unit representing 6.022 × 10²³ entities (Avogadro's number)
Molar Mass: Mass of one mole of a substance (g/mol)
Limiting Reactant: Reactant that is completely consumed and limits product formation
Theoretical Yield: Maximum amount of product possible based on stoichiometry
Percent Yield: (Actual yield ÷ Theoretical yield) × 100%

Conversion Relationships:

Moles to Mass: Moles × Molar Mass = Mass (g)
Mass to Moles: Mass (g) ÷ Molar Mass = Moles
Moles to Molecules: Moles × 6.022 × 10²³ = Molecules
Molecules to Moles: Molecules ÷ 6.022 × 10²³ = Moles
Mole Ratio: Ratio of moles based on balanced equation coefficients

Balancing Chemical Equations:

Chemical equations must be balanced to correctly represent the law of conservation of mass. The number of each type of atom must be the same on both sides of the equation.

Example balancing process for the combustion of methane:

CH₄ + O₂ → CO₂ + H₂O

CH₄ + 2O₂ → CO₂ + 2H₂O

The balanced equation shows the correct stoichiometric ratios needed for calculations.

Limiting Reactant Concept:

In most real-world reactions, reactants are not provided in exact stoichiometric ratios. The reactant that is completely consumed first limits how much product can be formed.

To identify the limiting reactant:

Calculate the moles of each reactant available
Divide moles by the stoichiometric coefficient in the balanced equation
The reactant with the smallest value is the limiting reactant

Limiting Reactant Example:

For the reaction: 2H₂ + O₂ → 2H₂O

If you have 10 moles of H₂ and 8 moles of O₂:

H₂: 10 mol ÷ 2 = 5 mol of water possible
O₂: 8 mol ÷ 1 = 8 mol of water possible

Therefore, H₂ is the limiting reactant, and only 10 mol of water can be produced.

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Stoichiometry Visualization

Na/K

Atomic Mass Reference

Element	Symbol	Atomic Mass (u)
Hydrogen	H	1.008
Helium	He	4.0026
Lithium	Li	6.94
Beryllium	Be	9.0122
Boron	B	10.81
Carbon	C	12.011
Nitrogen	N	14.007
Oxygen	O	15.999
Fluorine	F	18.998
Neon	Ne	20.18
Sodium	Na	22.99
Magnesium	Mg	24.305
Aluminum	Al	26.982
Silicon	Si	28.085
Phosphorus	P	30.974
Sulfur	S	32.06
Chlorine	Cl	35.45
Argon	Ar	39.948
Potassium	K	39.098
Calcium	Ca	40.078

Values based on standard atomic weights

Molecular Formula Breakdown

Formula:H2O

Molar Mass:18.015 g/mol

Elemental Composition:

Hydrogen × 22.016 g/mol

11.2%

Oxygen × 115.999 g/mol

88.8%

Key Formulas

Moles to Mass:

m = n × MM

Where m is mass (g), n is moles (mol), and MM is molar mass (g/mol)

Moles to Molecules:

N = n × N_A

Where N is number of molecules, n is moles, and N_A is Avogadro's number (6.022 × 10²³ mol^-1)

Concentration:

Molarity = moles of solute / liters of solution

Units: mol/L or M

About the Stoichiometry Converter

Convert between moles, grams, and molecules in chemical reactions All conversions run instantly in your browser and nothing you enter is sent to a server.

Common Conversion Formulas

From	To	Formula
Moles (mol)	Mass (g)	g = mol × Molar Mass
Moles (mol)	Number of Molecules	Molecules = mol × 6.022 × 10²³ (Avogadro's number)
Reactant Moles	Product Moles	Product mol = Reactant mol × (Product Coefficient / Reactant Coefficient)