Moles to Volume Calculator for Gas – STP and Custom Conditions
Convert moles of gas to liters at STP or any temperature and pressure with our moles-to-volume gas calculator. Uses the ideal gas law for accurate results. Great for chemistry students and lab professionals.
The ideal gas law relates moles, volume, temperature, and pressure of a gas. At STP (Standard Temperature and Pressure), 1 mole of any ideal gas occupies 22.4 liters.
Ideal Gas Law
Where:
- P = Pressure (atm)
- V = Volume (L)
- n = Number of moles (mol)
- R = Gas constant (0.08206 L·atm/(mol·K))
- T = Temperature (K)
STP Conditions
| Standard | Temperature | Pressure | Molar Volume |
|---|---|---|---|
| STP (old) | 0°C (273.15 K) | 1 atm | 22.4 L/mol |
| STP (IUPAC) | 0°C (273.15 K) | 1 bar | 22.7 L/mol |
| SATP | 25°C (298.15 K) | 1 bar | 24.8 L/mol |
Example Calculation
Calculate the volume of 2 moles of gas at 25°C and 1 atm:
V = nRT/P = (2 mol × 0.08206 × 298.15 K) / 1 atm = 48.9 L
Enter values and calculate to see the chart
| Moles | Volume at STP | Volume at 25°C |
|---|---|---|
| 0.1 mol | 2.24 L | 2.45 L |
| 0.5 mol | 11.2 L | 12.2 L |
| 1 mol | 22.4 L | 24.5 L |
| 2 mol | 44.8 L | 48.9 L |
| 5 mol | 112 L | 122 L |
Choose conversion direction
Select "Moles to Volume" or "Volume to Moles" from the dropdown.
Enter values and conditions
Input moles or volume, plus temperature and pressure. Select your units.
Calculate
The calculator uses the ideal gas law to find the unknown value.
Why is 1 mole of gas 22.4 L at STP?
Plug STP values into PV = nRT: V = nRT/P = (1 mol)(0.08206)(273.15 K)/(1 atm) = 22.4 L. This is why the number appears so often in gas calculations.
When does the ideal gas law fail?
At high pressures (molecules are close together) and low temperatures (molecules move slowly), real gases deviate from ideal behavior. Use van der Waals equation for more accuracy.
How do I convert Celsius to Kelvin?
Add 273.15. 0°C = 273.15 K, 25°C = 298.15 K, 100°C = 373.15 K. The gas law requires absolute temperature (Kelvin) because 0 K is true zero energy.
Does the type of gas matter?
For ideal gases, no. One mole of any ideal gas occupies the same volume at the same T and P. Real gases differ slightly, but the ideal gas law treats all gases identically.
What's the difference between STP and SATP?
STP (Standard Temperature and Pressure) is 0°C and 1 atm or 1 bar. SATP (Standard Ambient Temperature and Pressure) is 25°C and 1 bar—closer to lab conditions.
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