Thermodynamics Flashcards
1
Q
Entropy =
A
Sum of entropy of products minus sum of entropy of reactants
2
Q
Spontaneous reactions must be
A
Either exothermic or have a positive entropy
3
Q
Factors that affect entropy
A
Number of molecules
Temperature
Complexity of the molecule
Randomness of the molecule
4
Q
Gibbs free energy =
A
Enthalpy change - (temp x entropy change)
Spontaneous reaction
Gibbs energy is negative
5
Q
> 200 =
< - 200 =
0-200 =
-200 - 0 =
A
Completion
No reaction
Equilibrium products dominant
Equilibrium reactants dominant
6
Q
Entropy of surroundings =
A
- enthalpy change / temp
7
Q
Entropy units
A
J mol-1 k-1
8
Q
Why a reaction may not occur at room temperature??
A
The reaction has a high activation energy
9
Q
A reaction is feasible if…
A
Gibbs is less than or equal to zero
