Question

What are the limitations of the first law of Thermodynamics?

Answer 1

The internal energy is a state variable in a thermodynamic system that is in equilibrium (E). The difference in internal energy between two systems is equal to the heat transfer into the system minus the work done by the system.

Complete answer:
According to the first rule of thermodynamics, the universe's energy remains constant. It can be transferred between the system and the environment, but it cannot be produced or destroyed. The law is primarily concerned with changes in energy states as a result of work and heat transmission. It reinterprets the notion of energy conservation.
Heat is a type of energy, according to the First Law of Thermodynamics, and thermodynamic processes are thus subject to the concept of energy conservation. Heat energy cannot be generated or destroyed in this way. It can, however, be moved from one area to another and transformed into and out of other types of energy.
The first rule of thermodynamics has certain limitations, which are detailed below:
1. There are no restrictions on the passage of heat in either direction: the first law creates a clear link between the heat absorbed and the work done by a system. The first law does not state whether or not heat may move from a cold to a hot end. For example, freezing ice to a low temperature will not allow us to extract heat from it. There is some outside work to be done.
2. Does not indicate if the reaction is viable: the first law does not specify whether a process is feasible or not. For example, when a rod is heated at one end, equilibrium must be achieved, which is only achievable with some energy expenditure.
3. It is impossible to transform heat energy into an equivalent quantity of labour in practise.

Note:
The total energy of an isolated system is constant, according to the first rule of thermodynamics. Energy may be converted into other forms, but it cannot be generated or destroyed. According to this rule, some of the heat supplied to the system is utilised to modify the internal energy, while the remainder is employed by the system to perform work.