Steve,

 

Hello.  How would you go about solving this problem?

 

Antifreeze is a 50/50 misture by volume of ethylene glycol and water.  The density of ethylene glycol, HOCH₂H₂OH, is 1.11 g/ml and the density of water is 0.998 g/ml.  Assuming that the ethylene glycol is non-volatile, calculate the vapor pressure lowering of the solution at 100. ºC, the normal boiling point of water.

 

Thanks!