Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Can a system have negative entropy? Ask Question. Asked 4 years, 3 months ago. Active 6 months ago. Viewed 16k times. Improve this question. Scott Weinblatt 3 3 3 bronze badges. Pooja Pooja 57 1 1 gold badge 2 2 silver badges 4 4 bronze badges.
When a physicist talks about a closed system, what he means is one in which there is no exchange of mass, heat, or work with the surroundings; this is what we engineers call an isolated system. In engineering and most thermo books , a closed system is one in which there is no exchange of mass with the surroundings; exchange of heat and work are allowed. See the following link: google. But, if the system is isolated i. So its entropy can only increase or remain constant.
Show 5 more comments. Active Oldest Votes. Improve this answer. This heat energy was localized and orderly inside the loaf of bread, then it became less localized and less orderly as it dispersed into the room. Scientists have a name for the disorderly dispersal of energy: entropy. Entropy is primarily related to the way that energy spreads out, but matter is indirectly involved in entropy changes because energy dispersal can cause matter to enter a more disordered state.
For example, compressed gas molecules will naturally spread out into greater disorder as a result of random molecular motion induced by thermal energy. It is difficult to quantify degrees of energy and matter dispersal, so introductory discussions of entropy focus on how entropy changes when a particular event or reaction takes place. A negative change in entropy indicates that the disorder of an isolated system has decreased. For example, the reaction by which liquid water freezes into ice represents an isolated decrease in entropy because liquid particles are more disordered than solid particles.
Re: negative entropy Post by Srbui Azarapetian 2C » Sun Feb 04, pm The change in entropy can be negative, and when this is the case, you can think of it as a system becoming more ordered.
An example would be of condensation, in the transition from a gas high entropy state to a liquid low entropy state. Because of this, I don't think there is any way that you'd be able to have a system with a negative entropy.
Re: negative entropy Post by Ridhi Ravichandran 1E » Mon Feb 05, am There is no such thing as negative entropy, but a negative change in entropy exists. For example, a reaction that condenses from a gas to liquid would have a negative delta S because the liquid would occupy less possible states than the gas due to the decrease in temperature and volume. The third law of thermodynamics holds that "The entropies of all perfect crystals approach zero as the absolute temperature approaches zero.
0コメント