# Final Equilibrium Temperature

## Homework Statement

An adiabatically isolated system consists of 1 mol of a diatomic gas 100K and 2 mol of a solid at 200K separated by a rigid adiabatic wall. Find the equilibrium temperature of system after adiabatic wall is removed, assuming that the solid obeys the Dulong-Petit law.

## Homework Equations

mgascgas(T-100) = msolidcsolid(200-T)

mgascgas = Qgas = 5/2 nRT ( 5 is degree of freedom, I guess so)

## The Attempt at a Solution

5/2 nRT = Q = msolidcsolid(200-T)

171K

Redbelly98
Staff Emeritus
Homework Helper

## Homework Statement

An adiabatically isolated system consists of 1 mol of a diatomic gas 100K and 2 mol of a solid at 200K separated by a rigid adiabatic wall. Find the equilibrium temperature of system after adiabatic wall is removed, assuming that the solid obeys the Dulong-Petit law.

## Homework Equations

mgascgas(T-100) = msolidcsolid(200-T)

mgascgas = Qgas = 5/2 nRT ( 5 is degree of freedom, I guess so)

## The Attempt at a Solution

5/2 nRT = Q = msolidcsolid(200-T)

171K
I agree with that answer, though you didn't really show how you got it. You haven't shown how you used the Dulong-Petit law, and msolid shouldn't be part of the calculation.

The answer was given on back pages of the book. I have not got any answer yet. I dont know how they got that answer.

Redbelly98
Staff Emeritus