The freezing point of oxygen is -218.79 C and hydrogen is -252.8 C. Which freezes first? How much colder does it have to be for both to freeze?

Question

It's an integer word problem.

Answer 1

With falling temperature, the substance with the highest freezing point freezes first, so that is oxygen in this problem.  For hydrogen to freeze too, the temperature would have to drop an additional amount equal to the difference in the freezing points of hydrogen and oxygen.  

 

ΔT = -252.8 - (-218.79) = -34.01 C 

 

The temperature would have to drop an additional 34.01 C below the freezing point of oxygen for the hydrogen to freeze.