How much m3 of condensates correspond to 1 m3 steam?

Answer 1

First we start with a constant. At STP (273 K, 1 atm), 1 mole of gas occupies 22.4L or 0.0224 m3.

So then we use V1/T1 = V2/T2 with temperature in Kelvin.

0.0224 m3 / 273 K = V2 / 373 K (I am going to assume that the steam is not superheated, and remains at 100 C or 373 K)

Multiply 373 K to both sides of the above equation, and we get: V2 = 0.0306 m3

Now that I have calculated that 1 mole of steam (or any gas at 100 C) takes up 0.0306 m3 of volume, I can find how many moles of steam occupy 1 m3.

1 m3 / (0.0306 m3/mole) = 32.7 moles

Since you asked how many m3 of water corresponds to 1 m3 steam, we must then convert our 32.7 moles of H2O into a volume. This require the use of two additional constants: the molar mass, and density of water.

The molar mass of water is approx. 18 g/mole. The density of water is 1 g/cm3.

Our cubic meter of steam weighs: 32.7 moles * 18 g/mole = 588.1 g

And so this amount of steam, when condensed, occupies 588.1 cm3.

Finally, we multiply this quantity by a conversion factor (1 = 10-6 m3 / 1 cm3) to obtain the result in m3.

588.1 cm3 * (10^-6 m3 / 1 cm3) = 0.000588 m3, or 5.88*10-4 m3

Answer 2

The volume of condensates formed by 1 m3 of steam depends on the specific heat capacity and the thermal conditions of the system. Generally, when steam condenses, it reduces in volume by a factor of roughly 1600, so 1 m3 of steam would condense into approximately 0.000625 m3 (or 0.625 liters) of water.