Entropy
(S) A measure of the amount of disorder of the particles in a system.
Particle behavior in a system with high entropy
The particles are more spread out and moving more.
Particle behavior in a system with low entropy
The particles are not as spread apart and are moving less
Order of states of matter for increasing entropy
Solid, liquid, gas
Combination of what substances lead to increased entropy
The combination of pure substances to form homogeneous or heterogeneous mixtures
An increase in the number of moles of gas effect on entropy
Increase in entropy
An decrease in the number of moles of gas effect on entropy
Decrease in entropy
The same number of moles of gas effect on entropy
Entropy with stay the same
Sign for standard entropy values
S⦵
Sign for standard entropy change
ΔS⦵
The standard entropy of a substance
Entropy change from heating the substance from absolute zero (0 K) to the thermodynamic standard temperature of 298 K.
Standard entropy of a perfect crystal at absolute zero (0 K)
Zero
Standard entropy value of all substances
positive
Equation for the standard entropy change (ΔS⦵) for a reaction
ΔS⦵ = ΣS⦵ (products) − ΣS⦵ (reactants)
When spontaneous reactions will happen
Once the energy needed to start the reaction is provided, activation energy
Spontaneous reaction
A chemical reaction that favors product formation once the activation energy has been provided to start the reaction
Spontaneous reaction ability to occur without energy other than activation energy
Yes
Non-spontaneous reaction ability to occur without energy other than activation energy
No
Ball pushed down a hill type of reaction
Spontaneous
Ball pushed up a hill type of reaction
Non-spontaneous
The second law of thermodynamics
The total entropy of the universe tends to increase
The total entropy of the system and surroundings in spontaneous reaction
Must increase
Energy form in spontaneous reaction
A concentrated form to a dispersed form
Spontaneous proccess entropy equation
ΔS total = ΔS system + ΔS surroundings ≥ 0