Is this thermo process reversible?

AI Thread Summary
The discussion centers on whether mixing 0.8kg of water at 100°C with 0.8kg of water at 0°C is a reversible process. The calculated entropy change for the process is 81.1 J/K, leading to the question of reversibility. It is noted that entropy generation typically indicates an irreversible process. The confusion arises from the relationship between entropy and reversibility, with a reminder that irreversible processes generate entropy. The conclusion emphasizes that the mixing of water at different temperatures is indeed irreversible due to the increase in entropy.
hadroneater
Messages
56
Reaction score
0

Homework Statement


If 0.8kg of water at 100 celsius is mixed with 0.8kg of water at 0 celsius, is this process reversible?


Homework Equations


Entropy:
S = mcln(T_2/T_1)



The Attempt at a Solution


I've already calculated the entropy of the process, which is 81.1 J/K. But how do I know if it's reversible?
 
Physics news on Phys.org
How can it be reversible if entropy is generated? Entropy is generated for irreversible processes right? I think I remember this, but correct me if I'm wrong.
 
Oh. I seemed to have skipped that part of the lecture. Thank you!
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Entropy change for two masses of water mixed adiabatically
Replies
1
Views
2K
Change in Entropy When Mixing Water at Different Temperatures
Replies
5
Views
1K
Calculating the change in entropy, did I calculate correctly?
Replies
1
Views
2K
How does reversible =>no entropy change in the universe?
Replies
20
Views
3K
What is the entropy for an irreversible adiabatic process?
Replies
1
Views
2K
Thermodynamics Problem: Reversible and Irreversible Processes
Replies
1
Views
2K
Understanding entropy calculations
Replies
10
Views
6K
How to know whether a given process is reversible?
Replies
10
Views
2K
Closed cycle of an ideal gas
Replies
3
Views
1K
The maximum reversible work in thermodynamics (2)
Replies
1
Views
697

Hot Threads

Recent Insights

Back
Top