\sect{Change of boiling point with altitude}

Consider an atmosphere as an ideal gas whose average mass is $30$ gr/mole,
with uniform temperature ${T_A=27^oC}$. 
The atmospheric pressure at sea level ($h=0$) equals $P_0$. 

\Dn

We take liquid whose latent heat is ${Q=1000}$cal/mole,  
and we find that its boiling point is $105^oC$ at sea level, 
and $95^oC$ at the top of a mountain. 
Asume that the gas phase of this liquid is an ideal gas 
with density much lower than that of the liquid.

\Dn

(1) Calculate the atmospheric pressure $P_A$ as a function of height $h$. 

\Dn

(2) Calculate the liquid vapor pressure as a function of its temerature.

\Dn

(3) From above deduce what is the height of the mountain.


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