Spontaneous Change Chapter 10

Question 1

Entropy (S)

Answer 1

measurement of randomness that occurs in particles

Question 2

Change in S

Answer 2

Change in entropy between states

Question 3

What does an increase in Entropy lead to ?

Answer 3

Spontaneous processes

Question 4

Entropy Macroscopic Values

Answer 4

P, V, n, and T

Question 5

3rd law of thermodynamics

Answer 5

S of a pure perfect crystal at 0k is 0

Question 6

Equation of entropy

Answer 6

S= 0 when (Q/weird looking thing)= 1

Question 7

Standard Molar Entropy Formula

Answer 7

Change in S = S prod - S reactants
It is equivalent to the change in enthalpy

Question 8

2nd law of thermodynamics

Answer 8

Large molecules are assemebled from smaller ones and (Sf-Si univ) = (Sf-Si)sys + (Sf-Si)surr > 0

Question 9

Change in Surr formula

Answer 9

dependent on change in enthalpy and change in temperature.
- Transferring energy to surroundings = lowest possible energy state for system.
- Energy transfer is maximized at lower temperature
(Sf-Si) = -(Hf-Hi)sys / T

Question 10

What does it mean when change in Surr>0

Answer 10

It means reaction is irreversable because it will take on less entropy from surroundings.

Question 11

Gibb-Helmholtz Equation

Answer 11

It’s a representation of a spontaneous and closed system.
(Gf-Gi) < 0
Formula (Gf-Gi) = (Hf-Hi) - T(Sf-Si)

Question 12

3 possibilies in Gibb- Helmoholz equation

Answer 12

(Gf-Gi) < 0 ( Spontaneous) exergonic
(Gf-Gi ) > 0 (non spontaneous) endergonic
(Gf-Gi) = 0 Equilibrium

Question 13

Entropy (S)

Answer 13

The measure of the number of microstates or unavailability to do work
Ex: Microstates: q/T

Question 14

Gibbs Free energy

Answer 14

Maximum amount of work possible (available) in a closed, reversable system at constant T and P.
Ex: Enthalpy (H) Degrees of Freedom (S)
U-w-TS (leftover E)

Question 15

Spontaneous processor

Answer 15

A process that is capable of proceeding in a given direction without outside intervention.
Examples: Combustion rxns. Once it starts it continues on its own
Or
Iron rust spontaneously in air.

Question 16

Nonspontaneous Process

Answer 16

Will not occur without outside intervention.

Question 17

Are Endothermic rxn be Spontaneous?

Answer 17

YES, Endothermic can be spontaneous and Exothermic rxns be non-spontaneous.
Example: The melting of ice is endothermic
or
The freezing of water is exothermic

Question 18

Endothermic process formula

Answer 18

Examples (H2O) s –> (H2O) l
(Hf-Hi) fusion = 6.01 kJ/mol

Question 19

Exothermic reactions

Answer 19

Example: (H2O) l —> (H2O) s
(Hf-Hi)fr = - (Hf-Hi)fus = -6.01 kj/mol

Question 20

Table of Spontaneous rxns related to T>0

Answer 20

Melting Ice at 1 atm (Endothermic)
- T<0C: Nonspontaneous
- T = 0C: Reversable
- T > 0C: Spontaneous
Freezing water at 1 atm (Exothermic)
T<0 C: Spontaneous
T = 0C: Reversable
T> 0C: Nonspontaneous

Question 21

Atoms, molecules, and ions tend to do what?

Answer 21

Spread themselves out

Question 22

Homogenous gas mixtures are more likely to do compared to the state of two gases..

Answer 22

Be seperated

Question 23

Entropy(S) change related to heat formula.

Answer 23

(Sf-Si) = qrev/ T
Process is reversable only if system is in equilibrium the entire process.
- Melting at melting point
- Vaporization at 1 atm at boiling point
(No temp change during process)