Thermodynamics, Statistical Physics, and Quantum Mechanics

166 SOLUTIONS

Had we assumedthatoxygen iscondensing at we would get

Thiscontradicts thefact thatoxygen boils at a highertemperature.

The saturated vapor pressure at K should be lessthan To

find the oxygen mass, we use the ideal gas law at where theoxygen

is juststarting tocondense(i.e., itspressure is and it is all gas). So

where is theoxygenmolar mass. For nitrogen a similar equation can

be written for

where is the molar mass of nitrogen. Dividing (S.4.60.5) by(S.4.60.6),
we obtain

4.61 Air Bubble Coalescence (Moscow Phys-Tech)

Writing the equilibriumconditions for the bubbles toexist, we find for the

pressure inside each originalbubble: