entropy Flashcards
what is entropy?
a measure of disorder
What dpes entropy explain
why spontaneous reactions occur on their own
Phsyical state: entropy
Solid
ordered, and regular =low entropy
Gas
disordered and random arrangement = High entropy
Why does dissolving a sold increase its enthalpy?
dissolved particles can move freely and aren’t ordered - change is positive
if there’s a positive sign/
change in state increases in entropy
if there’s a negative sign?
change in state decreases entropy
Calculation for entropy changes
Sproducts - S reactants
what is free energy change?
a measure of whether a reaction is feasible
when is a reaction feasible?
when the free energy change is less or equal to zero
the equation for FEG
AG = AH - TAS
The effect of temperature of feasibility
- if its an exo reaction and the entropy is positive
the reaction is feasible at all temperatures
if its an endo reaction the entropy change is negative
the reaction is not feasible at any temp
if its and endo reaction and positive entropy change
the reaction is feasible above certain temps
If the entropy is negative and the reaction is exo
its feasible below certain temps