Mechanical Engineering - Thermodynamics - Discussion
Discussion Forum : Thermodynamics - Section 2 (Q.No. 19)
19.
The free expansion process is a constant enthalpy process.
Discussion:
13 comments Page 1 of 2.
Akhila said:
7 years ago
The free expansion process is also called as constant internal energy process so the answer is false.
(1)
Mayur B said:
5 years ago
For ideal gases, as we know, internal energy and enthalpy are a function of temperature only, so if internal energy U remains constant, temperature T also remains constant which means enthalpy also remains constant.
(1)
Vikash said:
1 decade ago
In free expansion internal energy remains constant not enthalpy.
Rohit singh said:
1 decade ago
Free expansion is an irreversible process in it both internal energy and enthalpy remains constant.
Sreeju said:
1 decade ago
dH = dE+pdV.
In free expansion, the external work(pdV) is obtained from the internal energy of the system. In ideal condition the change in the internal energy and the pdV work is equal and opposite in sign(pdV=-dE).
So, dH=0. Enthalpy constant.
In free expansion, the external work(pdV) is obtained from the internal energy of the system. In ideal condition the change in the internal energy and the pdV work is equal and opposite in sign(pdV=-dE).
So, dH=0. Enthalpy constant.
Mohammed Riyas said:
10 years ago
Free expansion must be an irreversible non flow process. So internal energy should be constant.
Hari said:
9 years ago
Free expansion process: Q = Delta U + W = 0.
Enthalpy: U + PV.
So, Internal energy is =0.
Enthalpy = PV.
Enthalpy: U + PV.
So, Internal energy is =0.
Enthalpy = PV.
S Bera said:
8 years ago
In Free expansion process dQ=0,du=0,dw=0,enthalpy =0(const).
Aditya loachab said:
7 years ago
Throttling process is also called isenthalpic process in which enthalpy remains constant before and after throttling process so it's not a correct answer.
Sandeep said:
7 years ago
Initial and final enthalpy are same but we can not say this process is constant enthalpy process because during expansion enthalpy first increases then decreases.
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