First law of thermodynamics for closed system

State, see Figure 1.12. During the pressure build-up, the system can be described by means of the first law of thermodynamics for closed systems ... 

First law of thermodynamics for closed systems, 22-24, 45-46 as applied to ideal gases, 64-77 for flow processes, 30-35, 212-217 Flame temperature, 127n,... 

The first law of thermodynamics for closed systems can be written in the form... 

For a pure substance at rest with no electrical or magnetic effects, the first law of thermodynamics for a closed system is expressed for a differential change as... 

The next step is to write down the first and second laws of thermodynamics for the system. If the system is a closed one (no matter enters or leaves it), the statement of the combined first and second laws is... 

Equation (4.23) is known as the first law of thermodynamics for a closed system.] Keep in mind that a system may do work, or have work done on it, without some obvious mechanical device such as a pump, shaft, and so on, being present. Often the nature of the work is implied rather than explicity stated. For example, a cylinder filled with gas enclosed by a movable piston implies that the surrounding atmosphere can do work on the piston or the reverse a batch fuel cell does no mechanical work, unless it produces bubbles, but does deliver a current at a potential difference electromagnetic radiation can impinge on or leave a system and so forth. 

This relation is recognized from introductory subjects on thermodynamics. Recall that in equilibrium thermodynamics a local formulation is generally not needed, since the intensive state variables are independent of the space coordinates. This fundamental formulation of the total energy balance is known as the first law of thermodynamics for a closed system, which expresses the fundamental physical principle that the total energy of the system, Etotab is conserved (a postulate). 

One interesting feature of the differential form of the first law of thermodynamics for a pure material which does not exchange mass with its surroundings (i.e., a closed system) is that an exact differential (i.e., dU) is equal to the sum of two path-dependent inexact differentials heat input to the system (dq) and work performed on the system (dw) ... 

In this chapter we develop expressions that relate heat and work to state functions those relations constitute the first and second laws of thermodynamics. We begin by reviewing basic concepts about work ( 2.1) that discussion leads us to the first law ( 2.2) for closed systems. Our development follows the ideas of Redlich [1]. Then we rationalize the second law ( 2.3) for closed systems, basing our arguments on those originally devised by Carath odory [2-4]. Finally, by straightforward applications of the stuff equations introduced in 1.4, we extend the first and second laws to open systems ( 2.4). 

The First Law of Thermodynamics for a closed system (constant mass) is... 

In other words, the change in the internal energy of the system is strictly related to the amount of energy that is added to the system by heat transfer or mechanical work. Often, one will use the symbol A to describe the difference between two points, in which case the first law of thermodynamics for a closed system is written as... 

When applied to closed (constant-mass) systems for which the only form of energy that changes is the internal energy, the first law of thermodynamics is expressed mathematically as... 

Already, you should be thinking to yourself But the particles in solids really don t move that mnch and you are certainly correct. They do move or translate in the liquid state of that same solid, however, and don t forget about rotation and vibration, which we will see in subsequent chapters can be very important in solids. But along this line of thinking, we can simplify the First Law of Thermodynamics, which in general terms can be written for a closed system (no transfer of matter between the system and surroundings) as... 

The first and second laws of thermodynamics for a homogeneous closed system involving only PV work lead to the fundamental equation for the internal energy... 

For a closed system the first law of thermodynamics has defined an energy function called internal energy U, which is expressed as a function of the temperature, volume, and number of moles of the constituent substances in the system U = u(t, V, n, nc). Furthermore, the second law has defined a state property, called entropy S, of the system, which is also expressed as a function of state variables S =s(T,V,nl---nc). Thermodynamics presumes that the functions t/(r,V,n, " nj and 5(7, y, I nc) exist independent of whether the system is closed or open. The energy functions of U, H, F, and G, then, apply not only to closed systems but also to open systems. 

In Chap. 2 the first law of thermodynamics was applied to closed systems (nonflo processes) and to single-stream, steady-state flow processes to provide specifi equations of energy conservation for these important applications. Our purpos here is to present a more general equation applicable to an open system or to control volume. 

The first law of thermodynamics provides a description of the energy balance for a given process the second law provides a criterion for deciding whether or not the process will occur spontaneously. The second law of thermodynamics defines the entropy change (A5, in units of J K l) associated with a change in a closed system in terms of the heat absorbed by the system at constant temperature T ... 

Comparing this equation with the first law of thermodynamics dH 8q - VdP (for a closed system and for - dP), we obtain... 

Define the terras closed process system, open process system, isothermal process, and adiabatic process. Write the first law of thermodynamics (the energy balance equation) for a closed process system and state the conditions under which each of the five terms in the balance can be neglected. Given a description of a closed process system, simplify the energy balance and solve it for whichever term is not specified in the process description. 

For closed systems, the first law of thermodynamics establishes the existence of the function of state U. We now presume that this function must also exist when the number of moles varies in an arbitrary manner. 

The temperature field can be obtained by solving a partial differential equation, the so called heat conduction equation, which will be derived now. This requires the application of the first law of thermodynamics to a closed system, namely a coherent region of any size, imaginarily taken from the conductive body, Fig. 2.1. The volume of this region is V and it has a surface area A. The first law produces the following power balance for the region ... 

Let s apply the first law of thermodynamics to a closed system (i.e. a system that can exchange heat and work with its surroundings, but not matter). The first law for a closed system can be written as... 

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