Ideal Gas Law Calculator Formula
Understand the math behind the ideal gas law calculator. Each variable explained with a worked example.
Formulas Used
Pressure
pressure_atm = moles * 0.082057 * temperature / volumePressure (Pa)
pressure_pa = moles * 8.314 * temperature / (volume * 0.001)Variables
| Variable | Description | Default |
|---|---|---|
moles | Amount of Gas (n)(mol) | 1 |
temperature | Temperature(K) | 273.15 |
volume | Volume(L) | 22.414 |
How It Works
Ideal Gas Law
The ideal gas law relates the pressure, volume, temperature, and amount of a gas.
Formula
PV = nRT
where R = 0.082057 L·atm/(mol·K) or 8.314 J/(mol·K). This law is accurate for gases at moderate pressures and temperatures.
Worked Example
1 mole of gas at 273.15 K (0°C) in 22.414 L (STP conditions).
- 01P = nRT / V
- 02P = 1 * 0.082057 * 273.15 / 22.414
- 03P = 22.414 / 22.414
- 04P = 1.000 atm (as expected at STP)
Frequently Asked Questions
What is an ideal gas?
A theoretical gas with perfectly elastic collisions and no intermolecular forces. Real gases approximate ideal behavior at low pressures and high temperatures.
What is STP?
Standard Temperature and Pressure: 273.15 K (0°C) and 1 atm. At STP, one mole of ideal gas occupies 22.414 liters.
When does the ideal gas law fail?
At very high pressures or low temperatures, where intermolecular forces and molecular volumes become significant. The van der Waals equation corrects for this.
Learn More
Guide
How to Calculate Density
Learn how to calculate density using the formula density = mass / volume. Covers units, measurement techniques, buoyancy, and real-world applications with worked examples.
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