Thermodynamics Ideal Gases/Perfect Gases a Gases. Agas is a fluid which has no intrinsic shape, e and which expands indefinitely to fill any container ● in which it is held. Ideal gases 1. The amount of substance of which it is comprised, n(mole 2. The temperature of the gas, T (Kelvin) 3. The pressure of the gas, P(Pascal) 4. The volume occupied by the gas
Ideal Gases/Perfect Gases Gases: A gas is a fluid which has no intrinsic shape, and which expands indefinitely to fill any container in which it is held. Ideal Gases: 1. The amount of substance of which it is comprised, n (mole) 2. The temperature of the gas, T (Kelvin) 3. The pressure of the gas, P (Pascal) 4. The volume occupied by the gas, V (m3 ) Thermodynamics
Chapter 1 Ideal Gases/Perfect Gases The four parameters are not e indepeodantng them are expressed in the gas laws a Gas Laws 1. Boyles law: Pv=constant at constant T and n e2. Charles law: VacT at constant P and n 3. Avogadros Principle: Von at constant P and T Ideal Gas Law /Perfect Gas Equation Pv=nRT R is gas constant (1.18)
Ideal Gases/Perfect Gases Gas Laws: 1. Boyle’s law: PV=constant at constant T and n 2. Charles’ law: VT at constant P and n 3. Avogadro’s Principle: Vn at constant P and T Chapter 1 The four parameters are not independent. The relations among them are expressed in the gas laws. Ideal Gas Law/Perfect Gas Equation: PV = nRT R is gas constant (1.18)*
Chapter 8 Real gases
Chapter 8 Real Gases
Physical Chemistry Real gases Compression Factors Real gases do not obey the perfect gas equation exactly. The real gas is expressed as the compression factor a ehavior of a measure of the deviation from ideality of the be P (,1RT (8. 200K .20C CH, 500K N 1000K CHA 1000K 200K P 100200300 300600900
Compression Factors Real gases do not obey the perfect gas equation exactly. The measure of the deviation from ideality of the behavior of a real gas is expressed as the compression factor Z: RT PV Z P T m ( , ) (8.1) Real Gases Z P 200 K 500 K 1000 K 200 K 1000 K 0 300 600 900 3 2 1 0 CH4 Z P H2 0 100 200 300 1.2 1 0.8 0 0 oC N2 CH4 Physical Chemistry
Physical Chemistry Real gases Real Gas equations of State P+ RT (8.2) RT a 6 K van der Waals equation Ideal Gas Law/ Perfect Gas Equation PV=rt PV=nRT (1.18)
Real Gas Equations of State (V b) RT V a P m m − = + 2 2 m Vm a V b RT P − − = (8.2) van der Waals equation Ideal Gas Law/Perfect Gas Equation: PV = nRT (1.18)* PVm = RT Physical Chemistry Real Gases