State the first law for a closed system undergoing a change of state.
Answers
We can also say that energy will always be conserved. Heat and work, these are two different forms of energy. If heat energy is provided to the system by the surrounding then system may provide the work energy to the surrounding and similarly if work is being done upon the system then system may deliver the energy in terms of heat to the surrounding.
Hence, this is the basic concept of first law of thermodynamics. Now we will see here the first law of thermodynamics for a closed system undergoing a change of state. After that, in our next post, we will see first law of thermodynamics for an open system or control volume.
As we have discussed in our previous post “first law of thermodynamics for a closed system undergoing a cycle” that the algebraic summation of all energy transfer i.e. heat energy transfer and work energy transfer across the system boundaries will be zero. Or we can say that for a closed system undergoing a cycle, we will have following equation according to the first law of thermodynamics.
First law of thermodynamics for a closed system undergoing a cycle
But we must note it here that if system is not undergoing in a cyclic process but also we have one system which is undergoing a change of state then in that case above equation will not be applicable as above equation is only valid for a system which is going under a cycle.
So, what will be the equation of energy transfer across the system boundary according to the first law of thermodynamics for a closed system under a change of state?
Let we have one closed system which is undergoing a change of state and energies i.e. work energy and heat energy both are crossing the system boundaries. Net energy will be stored within the system and we must note it here that energies stored within the system will be termed as internal energy of the system or also termed as energy of the system.
Let us see the following figure, Q heat energy enters the system from surrounding and work energy W leave the system or we can also say that system is doing work W on the surrounding by taking Q amount of heat energy from the surrounding.
So, what will be the net amount of energy stored within the system during this process?
(Q-W) will be the net energy and it will be accumulated within the system and hence there will be increment in internal energy of the system as (Q-W) amount of energy will be stored within the system during this process.
Therefore according to the first law of thermodynamics, we have following equation for above thermodynamic process where system is under a change of state.
Q-W = ∆E
Where, ∆E is increase in internal energy of the system during the process
hope u understood...
mark it as brainlist
The first law for a closed system undergoing a change of state states
- According to the first law, when a system withstands a thermodynamic process which is a change of state then both heat and work transfer takes place. The net energy transfer is reserved within the system and is known as stored energy or total energy of the operation.When a process is enforced by a system the change in stored energy of the system is numerically proportional to the net heat interchange minus the net work interaction at the time of the process.
- The First Law of Thermodynamics states that work and heat are mutually exchangeable. The current propensity is to comprise all forms of energy.
- According to the first law, when a closed system undergoes a thermodynamic cycle then the net heat transfer is proportional to the network transfer. The cyclic integral of heat transfer is proportional to the cyclic integral of work transfer.
#SPJ6