All Problems

Phase Transformations

Problem 2.193

Find the mass of all molecules leaving one square centimetre of water surface per second into a saturated water vapour above it at a temperature \(t^{2}=100^{\circ} \mathrm{C} .\) It is assumed that \(\eta=3.6 \%\) of all water vapour molecules falling on the water surface are retained in the liquid phase.

Reveal Answer
μ=ηp0VM/2πRT=0.35 g/(scm2), where p0 is the standard atmospheric pressure\mu=\eta p_{0} V \overline{M / 2 \pi R T}=0.35 \mathrm{~g} /\left(\mathrm{s} \cdot \mathrm{cm}^{2}\right), \text { where } p_{0} \text { is the standard atmospheric pressure}