Thermodynamics Quiz

System and Surroundings

• A system is a part of the universe where observations are made.
• The surroundings are the rest of the universe, excluding the system.
• The universe is the combination of the system and its surroundings.

Types of Systems

• Open system: Exchanges both energy and matter with its surroundings (e.g., hot coffee in an open vessel).
• Closed system: Exchanges energy but not matter with its surroundings (e.g., hot coffee in a closed vessel).
• Isolated system: Exchanges neither energy nor matter with its surroundings (e.g., hot coffee in a thermos).

Properties of a System

• Extensive properties: Depend on the amount of matter in the system. Examples include energy, internal energy, volume, enthalpy, mass, and entropy.
• Intensive properties: Independent of the amount of matter in the system. Examples include density, pressure, temperature, molar volume, specific heat capacity, viscosity, and refractive index.

State and Path Functions

• State function: Depends only on the initial and final state of the system (e.g., temperature, internal energy, volume, enthalpy, mass, entropy).
• Path function: Depends on the path taken to reach a particular state (e.g., heat, work).

Thermodynamic Processes

• Thermodynamic process: A process where the temperature of the system remains constant.

• Adiabatic process: A process where no heat transfer occurs between the system and its surroundings (Q = 0).

• Isochoric process: A process where the volume of the system remains constant (ΔV = 0).

• Isobaric process: A process where the pressure of the system remains constant (ΔP = 0).

• Sign Conventions

  • Heat absorbed by the system: positive
  • Heat released from the system: negative
  • Work done by the system: negative
  • Work done on the system: positive

Internal Energy

• Internal energy is the total energy of a system in a specific state.
• Internal energy is a state function.

First Law of Thermodynamics

• Energy can't be created or destroyed; it can only change forms.

Free Expansion

• In a free expansion, the work done is 0, the heat is 0, and the change in internal energy is 0.

Enthalpy

• Enthalpy is the total heat content of a system (H = U + PV).

Heat Capacity

• Heat capacity is the amount of heat required to raise the temperature of a system by 1 degree or 1 Kelvin (C = Q / ΔT).

Types of Heat Capacity

• Molar heat capacity: Heat capacity of 1 mole of a system.
• Specific heat capacity: Heat capacity of a unit mass of a system.

Hess's Law

• The enthalpy change of a reaction is the same whether it occurs in one step or multiple steps.

Thermochemical Equations

• A thermochemical equation is a balanced chemical equation that includes the enthalpy change of the reaction.

Spontaneous and Non-Spontaneous Processes

• Spontaneous process: Occurs naturally without external intervention.
• Non-spontaneous process: Needs external energy or intervention to occur.

Entropy

• Entropy is a measure of the disorder or randomness of a system.

Second Law of Thermodynamics

• The entropy of the universe always increases in a spontaneous process.

Gibbs Free Energy

• Gibbs free energy is the maximum amount of useful work a system can perform at a constant temperature and pressure (ΔG = ΔH – TΔS).

Third Law of Thermodynamics

• The entropy of a perfectly ordered crystalline substance approaches zero as the temperature approaches absolute zero.

Test your knowledge on the principles of thermodynamics, including systems, properties, and processes. This quiz covers topics like energy exchange, extensive and intensive properties, and the First Law of Thermodynamics. Challenge yourself with matching properties and understanding adiabatic and isoboric processes.