PhysicsThermodynamicsA-Level
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Ideal gas law Calculator

Relate pressure, volume and temperature of a gas.

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Pressure

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Overview

The ideal gas law is an equation of state that relates the pressure, volume, temperature, and amount of a hypothetical ideal gas. It serves as a fundamental approximation for the behavior of many gases under various conditions by combining Boyle's, Charles's, and Avogadro's laws.

Symbols

Variables

p = Pressure, V = Volume, n = Moles, R = Gas Constant, T = Temperature

Pressure
Pa
Volume
Moles
mol
Gas Constant
J/molK
Temperature

Apply it well

When To Use

When to use: Apply this equation when gas particles are far enough apart that their individual volumes and intermolecular attractions are negligible. It is most accurate at high temperatures and low pressures, typical of many atmospheric and laboratory conditions.

Why it matters: It is essential for calculating the properties of gases in diverse fields such as meteorology, chemical engineering, and respiratory physiology. Understanding this law allows for the prediction of how gases will expand or contract in response to environmental changes.

Avoid these traps

Common Mistakes

  • Using Celsius instead of Kelvin.
  • Mixing liters and m³.

One free problem

Practice Problem

A 2.0 mole sample of oxygen gas is contained in a 5.0 liter vessel at a temperature of 300 K. Calculate the pressure exerted by the gas in atmospheres.

Moles2 mol
Volume5 m^3
Temperature300 K
Gas Constant0.0821 J/molK

Solve for:

Hint: Rearrange the formula to p = nRT / V and ensure the gas constant R is in L·atm/mol·K.

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. AQA A-Level Physics — Thermal Physics