In the "formula" field, enter the formula of the gas. This is necessary to calculate its molar mass (the calculation method is described in detail under the calculator). The default formula is C3H8, which is the formula for propane. Then choose the type of calculation - from kilograms to cubic meters or from cubic meters to kilograms, and enter the known value - kilograms or cubic meters respectively. You can also change the value of the molar volume of gas (which is also involved in the calculation, see details under the calculator), the default value is 24.055 liters - the volume of one mole of gas under normal conditions - 20°C, 1 atmosphere. For standard conditions (0°C, 1 atmosphere) - the volume of one mole of gas is 22.414. You can use the calculator Molar volume to determine the molar volume of a gas at other values of temperature and pressure.
Relationship between mass and volume of gas
So, as it was written above, liquefied gas is dispensed in kilograms. Knowing the mass in kilograms you can find out the corresponding amount of substance in moles - for this purpose the mass is divided by the molar mass (molar mass is calculated by the gas formula), as it is done in the calculator Convert grams to moles and moles to grams.
For a given temperature and pressure, the molar volume of all ideal gases will be the same - this follows from the ideal gas equation
Thus, knowing the number of moles of a gas, you can find out its volume by simply multiplying the number of moles by the molar volume of the gas at the corresponding temperature and pressure. Usually, it is either the molar volume at 20°C and 1 atmosphere (normal conditions), which equals 24.055 liters, or the molar volume at 0°C and 1 atmosphere (standard conditions), which equals 22.414 liters.
Speaking of liquefied gas, we are primarily talking about propane, which, unlike, for example, methane (natural gas), liquefies at room temperature and relatively low pressure, about 12-15 atmospheres. Therefore, propane cylinders are lighter and cheaper than others. A 55-liter household propane cylinder holds about 22 kilograms of gas in liquefied form, which, according to the calculator, at 20°C and 1 atmosphere corresponds to about 12 cubic meters of gas.