STUDY4MECHANICAL for Mechanical Engineers

Some important point on the difference between characteristics gas constant and universal gas constant are explained below. Let us check out one by one below. You can also check out characteristics equation of gas , and general gas equation to know more about it. Difference between characteristics gas constant and universal gas constant: Constant gas characteristics vary from gas to gas but the constant of universal gas is fixed. If you working at human scales, then use universal gas constant, whereas if you want to gas constant that defined per unit mass of a specific gas, then use the specific gas constant.  The characteristic gas constant in equation P = RT is the value of R for a given gas for use. It is equal to the constant of universal gas divided by the molar mass of the particular gas. Characteristics gas Constant applicable for an ideal gas, whereas universal gas constant applicable for a real gas.  Units: Characteristics gas constant - k J / kg K and Univers

Characteristics equation of a gas is the modified equation of general gas. If the volume in a general gas is taken as 1 kg of gas, then the constant C is represented by another constant R.  Thus, the general gas equation may be rewritten as follows.  P V = R T R = Characteristics gas constant or Simply gas constant For any mass m kg of gas, the equation may be rewritten as follows. m P V = R T OR P V = m R T P = m / V  ×  R T Let we take m / V = ƿ  P = ƿ R T Where, P = Pressure ( 1 bar = 100  KN/m 2 ) R = Gas constant (287 J / kg K = 0287 k J / kg K) ƿ = Density of the given gas

The combined gas law or general gas laws give us the relation between the two variables when the third variable is constant. This law is obtained by Laws of a perfect gas . Boyle's and Charles's law are combined together, which gives us a general gas equation. It shows the relationship between pressure, temperature, and volume for a fixed mass of gas. PV = KT  By the above formula,  P 1   × V 1 / T 1 = P 2  × V 2 / T 2 With the addition of the Avogadro's law, the combined gas law develops into the ideal gas law which is explained below.  PV = nRT Where, P = Pressure V = Volume n = number of moles R = Universal gas constant T = Temperature Where R = Universal gas constant = 8.314 kPa L / mol K  An equivalent formula for this gas law is following below.  PV = kNT Where, k = Boltzmann constant (1.381 ×10 −23  J·K −1   in SI units) These all equations which we explained above are exact only for an ideal gas, which neglects

What is perfect gas? A perfect gas is also called an ideal gas. It may be defined as a state of a substance, whose evaporation from its liquid state is complete. Intermolecular forces are neglected, in perfect gas models. The gas law was developed when scientists began to realize the relationship between pressure, volume, and temperature of a sample of gas. That gas could be obtained which hold to an approximation of all gases.  So overall, we can say that the physical properties of a gas are controlled by the following three variables: The pressure exerted by the gas Volume occupied by the gas The temperature of the gas The behaviour of this perfect gas, undergoing any change in three variable above listed, is governed by the given four basic laws of a perfect gas.  Perfect Gas Law: Boyle's Law Charles's Law Gay-Lussac's Law Avogadro's Law Let we explained these laws in details below.  Boyle's Law Robert Boyle studied the re

The basic principles of thermodynamics were expressed originally in three laws. But it was decided after that, that a more basic law had been ignored. It had seemed so clear it didn't have to be clearly mentioned. Scientists agreed that this most basic law had to be included to form a full collection of laws. The name of this law is the zeroth law of thermodynamics. Now let us understand all the laws in brief one by one below.  Define laws of thermodynamics: Zeroth Law of thermodynamics This law states that when the two systems are in thermal equilibrium with a third system then they are in thermal equilibrium with each other.  First Law of Thermodynamics The first thermodynamic law is a variant of the energy conservation law, adapted for thermodynamic systems . This law states that the total energy of an isolated system is constant, energy can be transformed from one form to another, but can be neither created nor destroyed.  For exam

Definition of thermal equilibrium:  Two physical thermodynamic systems are in thermal equilibrium when there are variations in temperature from point to point of an isolated system. OR If there is no net thermal energy flow between them, when connected by a heat-permeable pathway. When there are no further changes are observed, the system is said to be in thermal equilibrium.  Thermal equilibrium performs on the zeroth law of thermodynamics . 

What are the properties of a system? The properties of the system in thermodynamics are things such as mass, temperature, volume, and pressure. Properties are used to determine the current state of a substance. All the quantities which identify the state of a system are called properties of a system. The thermodynamic properties are divided into two types which are following. Types of thermodynamic properties: Extensive properties Extensive properties are called the properties whose value for the whole system is equal to the sum of their values for the individual parts of the system. Example: Total volume, Total mass, Total energy of a system Intensive properties The properties whose value for the entire system is not equal to the sum of their values for the individual parts of the system are called intensive properties.  Example: Temperature, Pressure, Density