Thermodynamics Flashcards
What is a System?
A collection of material objects, enclosed from the surrounding area
Types of systems include isolated, closed, and open systems.
What is an Isolated System?
A system with no exchange of matter or energy with the surroundings
Example: A thermos flask with a sealed lid.
What is a Closed System?
A system that exchanges energy but not matter with the surroundings
Example: A sealed container that can be heated.
What is an Open System?
A system that exchanges both matter and energy with the surroundings
Example: A boiling pot of water.
What is Energy?
The measure of matter movement during transformation from one form to another
Types of energy include mechanical, thermal, chemical, and electrical energy.
What is Mechanical Energy?
Energy associated with motion or position
Includes kinetic energy (due to motion) and potential energy (due to position).
What is Thermal Energy?
Energy from the random motion of atoms and molecules
Example: Heat in a warm cup of tea.
What is Chemical Energy?
Energy stored in chemical bonds
Example: Energy released during digestion or combustion.
What is Electrical Energy?
Energy due to the motion of charged particles
Example: Electricity powering a bulb.
What is Work?
The measure of energy conversion from one form to another
Types of work include mechanical, chemical, osmotic, and electrical work.
What is Mechanical Work?
Energy used to move body components against mechanical forces
Example: Lifting a weight.
What is Chemical Work?
Energy used in chemical reactions
Example: Protein synthesis.
What is Osmotic Work?
Energy used to transport substances against a concentration gradient
Example: Active transport in cells.
What is Electrical Work?
Energy used to move charged particles
Example: Generation of nerve impulses.
What is the First Law of Thermodynamics?
Total energy in a system remains constant; it can only change through energy exchange with the surroundings
Mathematical formulation involves change in internal energy, heat added, and work done.
What is Primary Heat?
Heat produced from metabolic processes
Example: Friction of blood flow in vessels produces heat.
What is Secondary Heat?
Heat produced due to electrical resistance
Example: Muscle contractions producing heat.
What is the Second Law of Thermodynamics?
All energy conversions are accompanied by energy dissipation in the form of heat, which cannot be fully converted back into other forms of energy.
What is a Reversible Process?
A process where the system can return to its initial state without external energy
Example: Idealized gas compression/expansion.
What is an Irreversible Process?
A process that cannot return to the initial state without external energy
Example: Friction, real-world chemical reactions.
What is Entropy?
A measure of the amount of energy unavailable to do work
Involves heat produced and absolute temperature.
How does Entropy behave in Reversible Processes?
Entropy remains constant or changes predictably.
How does Entropy behave in Irreversible Processes?
Entropy increases due to heat dissipation.
What is Thermodynamic Equilibrium?
A state with no energy or matter exchange; free energy = 0, entropy = maximum.
What is a Steady State?
A state where energy and matter exchange occur, but system parameters remain constant
Example: Blood flow in the human body.
What is a similarity between Thermodynamic Equilibrium and Steady State?
Both involve constant system parameters.
What is the Coefficient of Effectiveness?
The effectiveness of a system’s ability to convert free energy into work.
In irreversible processes, part of the free energy dissipates as heat, reducing the work performed.
What is the Coefficient of Efficiency for reversible processes?
100% efficiency
This indicates that all free energy is converted into work without any loss.
What is the implication of Prigogine’s Theorem?
In a steady state, the speed of entropy production caused by irreversible processes is positive and at its minimum among all possible values.
This shows how systems minimize entropy production while maintaining efficiency.
How do living systems self-regulate?
By maintaining homeostasis (steady state) and minimizing entropy production.
An example is body temperature regulation.
What happens to free energy and entropy at life?
Free Energy: High, Entropy: Low
Cells perform work actively, keeping the system organized.
What changes occur in free energy and entropy at death?
Free Energy: Decreases, Entropy: Increases
The system loses organization and moves toward equilibrium.
What characterizes a steady state in living systems?
Free Energy: Maintained at a constant level, Entropy: Increases but remains minimized.
This allows continuous work through active regulation.
What occurs in stationary conditions (thermodynamic equilibrium)?
Free Energy: Reaches zero, Entropy: Maximum
The system has lost organization and is at equilibrium.
Define Internal Energy.
Total energy in the system, combining usable and unusable energy.
It includes free energy, temperature, and entropy.
What is Free Energy?
Usable energy for work (e.g., ATP in biological systems).
This energy is available for performing biological processes.
What is Bound Energy?
Useless energy dissipated as heat and unavailable for work.
It represents energy that cannot be harnessed for useful tasks.
