Master the First Law of Thermodynamics

Study Notes

The first law of thermodynamics is a formulation of the law of conservation of energy.
It distinguishes between heat and thermodynamic work for a system of constant matter.
The law of conservation of energy states that the total energy of any isolated system is constant.
Matter and energy can be converted into one another without violating the first law.
The law can be expressed as a formula involving internal energy, heat, and thermodynamic work.
The ideal isolated system is often used as a model, but practical systems require consideration of internal reactions and transfers of matter.
The first explicit statement of the first law of thermodynamics was made by Rudolf Clausius in 1850.
The concept of internal energy is of "enormous interest" and can only be inferred by differencing actual measurements.
The "mechanical approach" postulates the law of conservation of energy and distinguishes between adiabatic and non-adiabatic walls.
Energy can be transferred from one thermodynamic system to another in association with transfer of matter.
The first law of thermodynamics relates to the conservation of energy in a system.
It can be expressed in terms of work done and heat transferred.
The law applies to closed systems and can be stated in various ways.
A cyclic process involves the net work done and heat taken in by the system.
The mechanical equivalent of heat is a constant of proportionality.
The sign convention for work can vary depending on the writer or organization.
The change in internal energy of a closed system is equal to the net energy added as heat minus the thermodynamic work done.
The terms "heat" and "work energy" refer to actual physical processes, while internal energy is a mathematical abstraction.
Different combinations of heat and work can achieve the same change in internal energy.
The law is of great importance and generality and has an early origin in the nineteenth century.
The first law of thermodynamics refers to closed systems and the internal energy of a phase in equilibrium is a function of state.
Carathéodory's 1909 version of the first law refrained from defining or mentioning temperature or quantity of heat transferred.
Heat is defined as a residual difference between change of internal energy and work done on the system.
The first law was induced from empirically observed evidence, including calorimetric evidence.
Adiabatic processes involve transfer of energy as work but not as heat.
For all adiabatic processes that take a system from a given initial state to a given final state, the respective eventual total quantities of energy transferred as work are one and the same.
The work done on the system is defined and measured by changes in mechanical or quasi-mechanical variables external to the system.
Evidence shows that to increase the temperature of a system, the qualitative kind of adiabatically performed work does not matter.
A change from one state to another may be conducted in several stages, but it needs to be shown that the time order of the stages, and their relative magnitudes, does not affect the amount of adiabatic work that needs to be done for the change of state.
The first law of thermodynamics provides the definition of heat via the law of conservation of energy and the definition of work in terms of changes in the external parameters of a system.
The first law of thermodynamics applies to closed systems.
Work and heat are the two ways energy can be transferred to or from a system.
Work and heat transfers can occur simultaneously in a reversible process.
The work and heat transfers must belong to the same particular reversible process.
The first law for a particular reversible process can be written as the sum of work and heat transfers.
The law of conservation of energy applies when no work is done on a thermally isolated closed system.
The first law of thermodynamics applies to reversible processes.
The reversible process is defined by its particular reversible path through the space of thermodynamic states.
Work and heat transfers are not required to occur respectively adiabatically or adynamically.
The first law of thermodynamics expresses the conservation of energy for closed systems.

Description

Test your knowledge on the first law of thermodynamics with this quiz! From the law of conservation of energy to the distinction between heat and thermodynamic work, this quiz covers the fundamental concepts of the first law. Explore the various ways the law can be expressed and applied, as well as the significance of internal energy and closed systems. Challenge yourself to understand the principles behind adiabatic processes and reversible processes, and see how well you understand the conservation of energy for closed systems. Take this quiz to