Calculate the entropy change in the system, and in the surroundings and the total entropy change in the universe when during a process 75 J of heat flow out of the system at `55^(@)C` to the surrounding at `20^(@)C`.

Explanation

Heat flow (q) = 75 J
Entropy change = `DeltaS`= ?
Temperature of the system =`55^@C+273` = 328 K
Temperature of the surroundings =`20^@C`+273 =293 K
`DeltaS_"system"=q/T_"system"=75/328=0.2286 "J K"^(-1)`
`DeltaS_"surroundings"=q/T_"surroundings"=75/293=0.2559 J K^(-1)`
`DeltaS_"universe"`=Entropy change =`DeltaS_"system"+DeltaS_"surroundings"`
=0.2286+0.2559
`DeltaS_"universe"=0.4845 JK^(-1)`