Ideal gas law

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.

pV=nRT

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.

Tips

• Always convert temperature to Kelvin by adding 273.15 to the Celsius value.
• Check that your units for pressure and volume match the units of the gas constant R being used.
• Remember that n is the amount in moles; if given mass, divide by the molar mass first.

Common mistakes

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

Real-world example

Estimating gas pressure in a cylinder.

Open Interactive Equation

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