Thermodynamics

Notes

Ls 5 - Thermodynamics - Sugeeth Notes - 11 A - 19-01-2024.pdf

Quick Overview

1. Thermodynamics, the important terms

   • The System

   • The Surroundings

   • The Universe

   • The Types of Systems

     • Open System

     • Closed System

     • Isolated System

2. The State of the System

   • Path functions and State functions

Feature	State function	Path function
Dependence on path	Independent	Dependent
Description	Depends only on the current state of the system	Depends on the path taken to reach the current state
Result of multiple paths	Multiple paths can result in the same value	Multiple paths may result in different values
Examples	Temperature, pressure, volume, internal energy	Heat, work

  1. Pressure
  2. Volume
  3. Temperature
  4. Internal Energy
     - Work done
     - Heat
        - Conventions by IUPAC
     - The General case (The First Law of Thermodynamics)

        $$\triangle U = q \; + \; w$$

        Or another modification is present too.

  1. Enthalpy
  2. Entropy
  3. Heat Capacity
  4. Gibbs Energy

2. The Applications of the First Law

• Work done

  • Getting the General work done formula from physics

  • Converting it into terms of pressure

  • Taking and considering external pressure to be constant

  • Volume as a variable reference.

  • Adjusting it for IUPAC Conventions

  • The concept of Total Work done

  • Getting the newer, more adjusted formula for processes.

    • Conversion of external pressure into internal reference; using the idea of equilibrium.

    • Using the ideal gas equation to convert it into a more calculable reference

  • The concept of free expansion and Isothermal process

  • The concept of Isochoric Process

• Enthalpy

  • The concept of Enthalpy as a state function

  • The General equation of enthalpy (which is also the alternative equation of the First Law)

  • Conventions of Enthalpy

  • Extensive and Intensive Properties [Not to be confused with state functions]

  • Heat Capacity and Specific Heat, Molar Heat Capacity

  • The relationship between $C_p$ and $C_v$ for an ideal gas
  • The different standard enthalpies

1. Born-Haber Cycle

2. Entropy

3. Gibbs Energy (Free Energy)