Question

In a vertical frictionless piston and cylinder arrangement, 10 grams of water are 

heated to expand from 5 bar and 200oC to 500oC by a heat reservoir at 600oC. 

Find work and heat exchanged by water during this process. Find entropy 

change of water, heat reservoir and universe.

Answer 1

Gives

$M_1=10gm=0.01kg$

$$P_1=5 bar,T_1=200°c,T_2=500°c,T'=600°c$$

$Q=ms∆T$

$s_w=4184J/kg-K$

$$Q=0.01\times4184\times(500-200)=12552J$$

work(w)=12552J=12.552KJ

entropy change

$s=\frac{∆Q}{T'}$

$s=\frac{12552}{873}=14.37J/K$