Mid-terms Flashcards
(22 cards)
What is Enthalpy?
Measure of heat (H)
Enthalpy is a thermodynamic property that reflects the heat content of a system.
What is Entropy?
Measure of randomness (S)
Entropy quantifies the degree of disorder in a system.
What is Gibbs Free Energy?
Measure of available energy (G)
Gibbs Free Energy indicates the maximum reversible work obtainable from a thermodynamic system.
Define Spontaneous process.
A process that occurs on its own without any external factors.
Examples include water flowing from a faucet and wood burning.
Define Non-Spontaneous process.
A process that requires external factors to occur.
Examples include processes that need energy input to proceed.
What does the Thomsen-Berthelot Principle state?
All exothermic chemical processes are spontaneous.
This principle suggests a correlation between energy release and spontaneity.
What factors influence Entropy?
- Change of Temperature
- Number of Particles
Higher temperature increases kinetic energy, leading to higher entropy.
What is the 3rd Law of Thermodynamics?
If temperature is reduced indefinitely, a system will reach a condition with 0 entropy.
This law establishes an absolute reference point for the entropy of a perfect crystal.
What determines the spontaneity of a reaction according to Gibbs Free Energy?
- Enthalpy (H) should be negative
- Entropy (S) should be positive
A negative Gibbs Free Energy indicates a spontaneous reaction.
What happens if H is positive?
S must be larger than H to make G negative, resulting in spontaneity.
This reflects the balance needed between enthalpy and entropy for spontaneity.
What is Equilibrium?
A state where the forward and reverse reactions occur at the same rate.
At equilibrium, concentrations of reactants and products remain constant.
Define Equilibrium Constant (K).
The ratio of the concentrations of products to reactants at equilibrium.
K is calculated by multiplying the concentrations of products and dividing by the concentrations of reactants.
What is the difference between Homogeneous and Heterogeneous Equilibria?
- Homogeneous Equilibria: Uniform composition
- Heterogeneous Equilibria: Mixed phases (solid, liquid, gas)
This distinction is important for understanding the behavior of systems at equilibrium.
What is Le Chatelier’s Principle?
When a system at equilibrium is disturbed, it will shift to counteract the disturbance.
This principle helps predict how changes in concentration, temperature, or pressure will affect equilibrium.
What are the actions that can shift the equilibrium?
- Adding more Reactants
- Adding more Products
- Removing a Reactant
- Removing a Product
These actions either favor the forward or reverse reaction depending on the system’s conditions.
How does temperature affect equilibrium?
- Increase in temperature favors endothermic reactions (forward)
- Decrease in temperature favors exothermic reactions (reverse)
Temperature changes can significantly influence the position of equilibrium.
What is the Law of Mass Action?
At equilibrium, no apparent change in the state of the system is observed.
It describes the relationship between the concentrations of reactants and products at equilibrium.
Define Bronsted Acid.
A proton donor, typically a compound that releases hydrogen ions (H+).
Bronsted acids play a crucial role in acid-base chemistry.
Define Bronsted Base.
A proton acceptor, typically a compound that can accept hydrogen ions (H+).
Understanding Bronsted bases is essential for studying acid-base reactions.
What is a conjugate base?
The species that remains after an acid has donated a proton.
Conjugate bases are formed from acids during chemical reactions.
What is a conjugate acid?
The species formed when a base accepts a proton.
Conjugate acids arise in acid-base reactions where bases gain protons.
How does water act in acid-base reactions?
Water can act as both an acid and a base.
This dual nature is crucial for many chemical reactions and equilibria.
