Question

One kilogram water at $0^{o}C$ is brought into contact with a heat reservoir at ${100}^{o}C$. Find:
(a) Change in entropy when temperature reaches to ${100}^{o}C$.
(b) What is the change in entropy of reservoir?
(c) Change in entropy universe.
(d) The nature of process.

Answer 1

(a) $312cal{K}^{-1}$
(b) $-268.1cal{K}^{-1}$
(c) $43.9cal{K}^{-1}$
(d) Spontaneous
(a) $\Delta S=2.303n{C}_P\log \frac{T_2}{T_1}$
(b) $\Delta S_{resvoir}=-\frac{\Delta Q}{T}$
where $\Delta Q=ms\Delta T={10}^{5}cal$
(c) $\Delta S_{univ}==312-268.1$
(d) $\Delta S>0$, the process will be spontaneous