Question

Calculate the entropy change in the system if 20J heat observed by the system at constant temperature 10 degrees celcius

Answer 1

Calculate the entropy change in the system if 20J heat observed by the system at constant temperature 10 degrees celcius

Solution

Clausius defined the change in entropy of a thermodynamic system $(dS)$, during a reversible process, as:

$$dS = \frac{\delta Q}{T}$$

where

$\delta Q$ is a small amount of heat introduced reversibly to the system,

$T$ is a constant absolute temperature (in kelvins).

We are given:

$$\delta Q = 20J$$ $$T = 10{}^{\circ}C = 283.15\,K$$

Thus:

$$dS = \frac{\delta Q}{T} = \frac{20}{283.15} \approx 0.071\, \frac{J}{K}$$

Answer: $0.071\, \frac{J}{K}$