Thermodynamics is the study of heat (heat) that move. In thermodynamics you will a great deal about the system and the environment. Collection of objects called the system under review, while all who were around (outside) the system is called the environment.
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Outside of business done by the system, if heat is added (heated) or heat reduced (cooled) to the system. If heat is applied to the gases that cause changes in the volume of gas, out of business will be done by the gas. The work done by the gas when the volume change of the initial volume V1 to V2 in the final volume constant pressure p is expressed as the product of pressure with volume changes.
W = pΔV = P (V2 - V1)
In general, businesses can be expressed as an integral pressure against volume changes are written as
The gas is said to do business if the volume of gas becomes larger (or expand) and V2> V1. otherwise, the gas is said to receive a business (or business done on the gas) when the gas volume decreases or V2
Energy In
A gas which is in a certain temperature is said to have the energy within. Energy in the gas associated with the gas temperature and the microscopic properties of the gas. Although the gas does not make or receive a business, the gas can have energy that is not visible but is contained in the gas which can only be viewed in microscopic.
Based on the kinetic theory of gases, the gas consists of particles that are in a state of random motion. Particle motion is due to the average kinetic energy of all particles are moving. The kinetic energy is related to the absolute temperature of the gas. Thus, the energy can be viewed as the sum total of kinetic and potential energy contained and owned by particles in the gas in the microscopic scale. And, the energy in the gas is proportional to the absolute temperature of gas. Therefore, the gas temperature changes will cause changes in the gas energy. Mathematically, the change in the gas energy is expressed as
for monatomic gases
for diatomic gases
Where ΔU is the change of energy in the gas, n is the number of moles of gas, R is the general gas constant (R = 8.31 J mol-1 K-1, and ΔT is the change in gas temperature (in kelvin).
Law of Thermodynamics I
If the heat supplied to the system, volume and temperature will increase the system (the system will look to expand and increase the heat). Conversely, if heat is taken from the system, volume and temperature of the system will be reduced (the system looks and feels more cold shrink). This principle is an important law of nature and one form of energy conservation laws.
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Systems that are experiencing change in volume will make an effort and systems that are experiencing changes in temperature will experience a change in energy. Thus, the heat given to the system will cause the system to do business and experience in the energy change. This principle is known as the law of conservation of energy in thermodynamics or the law I called thermodynamics. Mathematically, the law of thermodynamics is written as I
Q = W + ΔU
Where Q is the heat, W is the business, and ΔU is the change in energy. Simply put, the law of thermodynamics I can be expressed as follows.
If an object (eg chips) is heated (or fried) which means that given the heat Q, objects (chips) will expand or increase in volume which means doing business and objects W (chips) will increase the heat (just try held, definitely hot deh!) which means experiencing a change in energy ΔU.
Process Isotermik
A thermodynamic system can undergo a process in which changes occur in the system. If the process that occurs takes place in a constant temperature, this process is called process isotermik. Due to take place in a constant temperature, no change in energy (ΔU = 0) and under the laws of thermodynamics I are given the same heat to the work performed by the system (Q = W).
Isotermik process can be described in a graph p - V below. The work done and heat system can be expressed as
Where V2 and V1 are the initial and final volume of gas.
Process Isokhorik
If the gas thermodynamic process in a constant volume, the gas is said to make the process isokhorik. Because gas is in a constant volume (ΔV = 0), the gas does not conduct business (W = 0) and given the same heat energy change it. Heat here can be expressed as heat of gas at constant volume QV.
QV = ΔU
Isobaric process
If the gas thermodynamic process by keeping the pressure remains constant, the gas is said to perform isobaric process. Because the gas is in a constant pressure, the gas doing business (W = pΔV). Heat here can be expressed as heat of gas at constant pressure Qp. Based on the law of thermodynamics I, on the isobaric process applies
Earlier it was written that the change in energy equal to the absorbed heat of gas at constant volume
QV = ΔU
From here the business of gas can be expressed as
W = Qp - QV
Thus, the work done by the gas (W) can be expressed as the difference of energy (heat) is absorbed gas at constant pressure (Qp) with energy (heat) is absorbed gas at constant volume (QV).
Adiabatic Process
In the adiabatic process no heat incoming (absorbed) or out (released) by the system (Q = 0). Thus, the work done by the gas as the energy changes therein (W = ΔU).
If a system contains a gas that originally had the pressure and volume respectively p1 and V1 experiencing adiabatic processes so that the pressure and volume of gas turned into p2 and V2, gas work done can be expressed as
Where γ is a constant obtained by comparison of gas molar heat capacity at constant pressure and volume and has a value greater than 1 (γ> 1).
Adiabatic process can be illustrated in the graph p - V curve with a shape similar to the graph p - V in the process isotermik but with a steeper curvature.
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