Ideal gas Equation in Thermodynamics

It has been established from experimental observations that the p-v-t behavior of gases at a low pressure is closely given by the following relation.

pv* =R*T (equation 1)

where R* is universal gas constant., 8.3143 J/mol K and v* is the molar specific volume, m3 / g mol. Dividing by the molecular weight ''u",

pv=RT (equation 2)

where v is the specific volume, in m3/kg, and R is the characteristic gas constant.

Substituting R= R* / u / uJ / Kg K, we get in terms of the volume V of gas,

PV = nR*T

PV = nRT (equation 3)

where n is the number of moles and m is the mass of the gas. Equation can be written for two states of gas.

P1V1 / T1 = P2V2 / T2

equation 1, 2 and 3 is called the ideal gas equation of the state. At very low pressure or density, all gases and vapors approach ideal gas behavior.

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