Skip to main content

Ideal Gas Moles Solver

Solve the amount of gas n from PV = nRT, or solve pressure, volume, or temperature instead. Defaults target moles. R = 8.314462618 J/(mol·K). Informational, not a pressure-vessel rating.

Rated 4.7 out of 5 based on 154 reviews

Results

How to solve ideal gas moles

  1. Keep Solve set to Amount n when you want moles. Leave the n field blank.
  2. Enter pressure, volume, and temperature with units that match your data.
  3. Read n in moles along with the other state variables converted for display.
  4. Switch Solve to pressure, volume, or temperature when that quantity is the unknown instead.

Ideal gas amount

n from PV = nRT

Ideal gas lawPV = nRT
Gas constant R8.314462618 J/(mol·K)
Pressure PConverted internally to pascals
Volume VConverted internally to cubic meters
Temperature TAbsolute temperature in kelvin
Amount nMoles of gas

What this spoke emphasizes

This page is the ideal gas engine with moles as the default unknown. About 1 atm, 22.4 L, and 273.15 K yields roughly one mole for an ideal gas near historical STP teaching values.

Pressure, volume, temperature, and moles

Pressure pushes on the container walls. Volume is the gas space. Temperature must be absolute for PV = nRT. Moles count how much gas is present. R ties the SI units together.

How PV = nRT is rearranged

Inputs convert to Pa, m³, and K. With Solve = n, the page computes n = PV / RT. Other solve targets rearrange the same relation. Invalid unit codes or non-positive required values throw errors.

Limits

Ideal gas model only. Real gases deviate at high pressure and low temperature. Not a vessel rating or safety calculation. See the disclaimer.

Ideal gas moles questions

Which R value does the page use?
R = 8.314462618 J/(mol·K) with pressure in pascals, volume in cubic meters, and temperature in kelvin.
Why is n blank by default?
Solve defaults to amount n, so the blank is the unknown the page fills from P, V, and T.
Is 22.4 L always one mole?
Only near the historical teaching STP point for an ideal gas. Change P or T and n changes.
Can I solve temperature instead?
Yes. Set Solve to Temperature, enter P, V, and n, and leave T blank.
How does this differ from the ideal gas hub?
Same engine and law. This spoke defaults to solving moles and frames the job around amount of gas.