Question

What is the change in entropy of helium gas with total mass 0.120 kg at the normal boiling point of helium when it all condenses isothermally to liquid helium? Assume that the normal boiling point of helium is 4.216 K and the heat of vaporization of helium is 2.09×10^4 J/kg .

Answer 1

-594.87666 J/kg

Step-by-step explanation:

m = Mass of Helium = 0.12 kg

T = Temperature = 4.216 K

`H_v` = Heat of vaporization =
`-2.09* 10^(4)\ J/kg`

Change in entropy is given by

`\Delta S=(mH_v)/(T)\\\Rightarrow \Delta S=(0.12* -2.09* 10^(4))/(4.216)\\\Rightarrow \Delta S=-594.87666\ J/kg`

The change in entropy is -594.87666 J/kg