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Ideal Gas Law Calculator (PV = nRT)

Calculate pressure (P), volume (V), number of moles (n), or temperature (T) of an ideal gas using the ideal gas law PV=nRT. Chemistry and physics calculator for students studying thermodynamics, gas behavior, and kinetic molecular theory. Supports various unit combinations.

Ideal Gas Law

PV = nRT

Variables:

  • PPressure (Pa or atm)
    Pressure (Pa or atm)
  • VVolume (Liters or m³)
    Volume (Liters or m³)
  • nNumber of moles (mol)
    Number of moles (mol)
  • RIdeal Gas Constant (0.0821 atm·L/mol·K or 8.314 J/mol·K)
    Ideal Gas Constant (0.0821 atm·L/mol·K or 8.314 J/mol·K)
  • TAbsolute temperature (Kelvin)
    Absolute temperature (Kelvin)

How to Use

  1. 1

    Select Target

    Choose the variable you want to find (Pressure, Volume, Mol, or Temp).

  2. 2

    Choose Units

    Make sure units are consistent (SI or ATM).

  3. 3

    Enter Data

    Enter the known variable values.

  4. 4

    Calculate

    Get the calculation result.

Examples

Finding Gas Volume

Problem:

1 mol of gas at 0°C (273 K) and 1 atm.

Solution:
  1. 1.R = 0.0821
  2. 2.V = nRT / P
  3. 3.V = 1 * 0.0821 * 273 / 1
Result:22.4 liters

The molar volume of a gas at STP is 22.4 liters.

Frequently Asked Questions

What is STP?
Standard Temperature and Pressure (0°C, 1 atm).
When is a gas considered ideal?
At high temperature and low pressure, where intermolecular interactions can be ignored.

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References