Register to reply

Entropy Variation - System, Neighborhood and Universe

by jaumzaum
Tags: entropy, neighborhood, universe, variation
Share this thread:
Mar18-13, 10:59 AM
jaumzaum's Avatar
P: 248
I learned ΔSuniv = ΔSsys + ΔSneib

If ΔSuniv > 0 the process is spontaneous.

But ΔS = Q/T right? Shouldn't Qsys = -Qneib? (The heat released by the system = - heat released by the neighborhood)
I cannot understand why this is wrong!

If it were the case, ΔSuniv would be always zero

Can anyone help me?

Phys.Org News Partner Chemistry news on
Scientists develop 'electronic nose' for rapid detection of C. diff infection
A new synthetic amino acid for an emerging class of drugs
Team pioneers strategy for creating new materials
Mar18-13, 02:01 PM
Sci Advisor
P: 3,593
##\Delta S=Q/T## only for reversible processes.For irreversible processes, ##\Delta S>Q/T##.

Register to reply

Related Discussions
Universe entropy variation of one body and a reservoir Advanced Physics Homework 3
The entropy of the universe? (attempts to define gravitational entropy) Cosmology 22
When will the entropy of universe(an isolated system) stop increasing? Classical Physics 1
How is the entropy of the universe increasing when entropy is simply transferred? Introductory Physics Homework 5
The expanding universe isn't in our neighborhood Astronomy & Astrophysics 3