ABSTRACT

From what we have just seen, it should be apparent that entropy depends on temperature. At the high temperature, where the motion of the molecules is restricted, the entropy is low. (In fact it is zero in the artificial example given in Box 1.2.) On the other hand, at low temperatures where the dis­ tribution of heat is more random, tho entropy is higher. The change in entropy of a system at temperature T when a small quantity of heat (!:1q) is slowly added or taken away can be expressed as

1.2)

We make the sign of 6.q positive if heat is added so that the entropy increases. Conversely, removing heat causes the entropy of the system to decrease.