Calculate moles and molar mass of a gas from pressure, volume, temperature, and the mass you weighed.
| Moles | – |
| M (g/mol) | – |
Use this calculator for a Dumas or syringe lab when you have pressure, volume, temperature, and grams, and you want n and M assuming an ideal gas.
n = PV / RT, with R = 8.314462618 J/(mol·K), then M = mass / n. Pressure is in pascals and volume in cubic metres (1 atm = 101325 Pa; 250 mL = 0.00025 m³). Enter temperature in °C or °F; the calculator converts to kelvin. Mass can be entered in grams (g), ounces (oz), or pounds (lb); the calculator converts to grams. Temperature must be above −273.15 °C.
This is the ideal-gas law. It does not include compressibility or vapour non-ideality.
P (Pa): Pressure in pascals. 1.00 atm is 101325.
V (m³): Volume in cubic metres. 250 mL is 0.00025.
Temperature: Gas temperature in °C or °F. Room temperature is about 22 °C.
Mass: Mass of the gas sample in g, oz, or lb.
Moles: Amount of gas n from PV/RT.
M (g/mol): Molar mass mass / n.
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