# B Energy needed to decrease or increase entropy?

1. Jan 25, 2017

### ahmed11

is incresing the entropy of low entropy system easier than trying to increase the entropy of a high entropy system?
or is it vice versa?
let's say it requires x amount of energy to increase a low entropy system, now will increasing an already high entropy system require 2x amount of energy or less than x amount of energy?

2. Jan 25, 2017

### jbriggs444

If your measure of "how hard is it to increase entropy" is the amount of energy required to produce an incremental change in entropy, be aware that this is one way of defining temperature. The higher the temperature, the more energy it takes.

From wiki (which in turn sources from various Thermo textbooks):

"If internal energy is considered as a function of the volume and entropy of a homogeneous system in thermodynamic equilibrium, thermodynamic absolute temperature appears as the partial derivative of internal energy with respect the entropy at constant volume.