Atkins & de Paula:
Physical Chemistry for the Life Sciences
The entropy of a sample with heat capacity that is independent of temperature, such as a monatomic perfect gas, increases logarithmically ( as ln(T) ) as the temperature is increased. The increase is proportional to the heat capacity of the sample.
The formula is
Where C is heat capacity (either Cp or CV), and temperature is changed from Ti to Tf.
To graph the change in entropy (J K-1) enter the parameter (i.e., C) and hit New Plot. Up to 5 plots can be
displayed at one time. The Clear button will remove all plots. To see the parameters for each plot hit the
Legend on/off button. The Redraw button will refresh the graph. This is useful when the function
domain (i.e., Tf / Ti ) has been changed. To see the value of each plot at a given point, move
your cursor to the desired location then click and hold.