By: Assoc. Prof Dr. Jahimin Asik @ Abd. Rashid ThermodynamicsThe Laws 1 In Chemistry, its always work done ON system. In physics, work done BY the system. Thermodynamic Variables State Functions - state variables of a system that only depends on the initial and final state of the system and not the path used to get to that state. Non-State Functions - state variables of a system that depends on the path used to get to that state. MathematicallyState Functions – exact differential, dU, dP, dU etc. Non-state Functions - Inexact differential, δw, δq 7 Heat Capacity Heat Capacity Heat Capacity Heat Capacity Heat Capacity Heat Capacity Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Example 3. A mole of an ideal, monoatomic gas is expanding freely from 15 L to 30 L against 1 atm external pressure at 25oC. Calculate ∆U, w and q if the gas expand; a) Reversibly Isothermal b) Irreversibly Isothermal Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Application of first law of thermodynamic Example 10L one mole of an ideal gas is expanding isothermally to 100L at 298K. Compare the entropy change between system, surrounding and universe if the process expanding i) Reversibly isothermal ii) Irreversibly isothermal against external pressure of 0.100 atm.
