Gas Stoichiometry Calculator
Relate gas volumes to moles and reaction stoichiometry at given conditions.
About Gas Stoichiometry Calculator
Because all gases occupy the same molar volume under identical conditions, gas volumes react in the same ratio as their coefficients. That is Avogadro’s law, and it lets volumes be used directly without converting to moles. Gas volume ratios equal coefficient ratios only at constant temperature and pressure, which is why both must be stated.
Formula
Gas Stoichiometry
n = pV ÷ RT, then apply the coefficient ratio; equal volumes contain equal moles
- molar volume
- Volume occupied by one mole at the stated conditions, 24.5 L at 25 °C and 1 atm
Worked example
With the default values below, Gas Stoichiometry Calculator returns Moles of Gas of 0.980977. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Volume of gasminimum 0 L
- 24 L
- Pressureminimum 0.01 Pa
- 101,325 Pa
- Temperatureminimum -272 C
- 25 C
- Coefficient of this gasaccepts 1–20
- 1
- Coefficient of the productaccepts 1–20
- 2
Results
- Moles of Gas
- 0.980977 mol
- Moles of Product Formed
- 1.961954 mol
- Product Gas Volume at the Same Conditions
- 48.0000 L
- Molar Volume at These Conditions
- 24.46540 L/mol
- Temperature
- 298.15 K
Step by step
- 1Values used
- 2Gas Stoichiometry
- 3Moles of Gas= 0.980977 mol
- 4Moles of Product Formed= 1.961954 mol
- 5Product Gas Volume at the Same Conditions= 48.0000 L
- 6Molar Volume at These Conditions= 24.46540 L/mol
- 7Temperature= 298.15 K
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Gas Stoichiometry calculated?
n = pV ÷ RT, then apply the coefficient ratio; equal volumes contain equal moles Because all gases occupy the same molar volume under identical conditions, gas volumes react in the same ratio as their coefficients. That is Avogadro’s law, and it lets volumes be used directly without converting to moles.
Why does Gas Stoichiometry matter?
Gas volume ratios equal coefficient ratios only at constant temperature and pressure, which is why both must be stated.
What values do I need to enter?
This calculator takes 5 inputs: Volume of gas, Pressure, Temperature, Coefficient of this gas, Coefficient of the product. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.