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Ideal Gas Law Calculator

Ideal gas law calculator

Compute moles n from pressure, volume, and temperature.

InputsChemistry3 fieldsLive

Result

1.000001701 mol

Uses n = PV/(RT).

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Advanced options
Formula
PV = nRT
so n = PV/RT

Symbol legend

Symbol Meaning Unit Copy
P Pressure atm
V Volume L
n Amount of gas mol
R Gas constant L.atm/(mol.K)
T Absolute temperature K
  • Enter pressure in atm, volume in liters, and temperature in kelvin.
  • Use gas constant R consistent with these units.
  • Solve n = PV/RT.
Example

Worked example: STP-like condition

  1. 1 P = 1 atm, V = 22.414 L, T = 273.15 K
  2. 2 n = PV/RT
  3. 3 n ≈ 1.00 mol

The gas amount is approximately 1.00 mol.

How
  1. Enter pressure (atm), volume (L), and temperature (K).
  2. Ensure temperature is absolute (kelvin).
  3. Read calculated moles n.
Avoid
  • Using Celsius instead of Kelvin.
  • Mixing incompatible pressure units with R value.
  • Applying ideal assumption to strongly non-ideal gas conditions.

Ref only. Verify values. Follow lab safety.

FAQ
Can I use Celsius input?

Convert to Kelvin first: K = C + 273.15.

Which R constant is used?

This setup uses R in L.atm/(mol.K) with pressure in atm and volume in liters.

Is this valid for real gases at high pressure?

Ideal gas law is an approximation and may deviate at high pressure or low temperature.

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