Chemistry final

Question 1

System

Answer 1

What we study

Question 2

Surroundings

Answer 2

Everything else

Question 3

Open system

Answer 3

Exchange of ENERGY and MATTER

Question 4

Closed system

Answer 4

Exchange of ENERGY only

Question 5

Isolated System

Answer 5

Does not exchange energy or matter

Question 6

spontaneous

Answer 6

Occurs under a set of conditions

Question 7

Nonspontaneous

Answer 7

Does not occur under a set of conditions (needs energy input)

Question 8

reversible process

Answer 8

the SYSTEM changes so that the system/surroundings can be returned to their original state by reversing the process. (maximizes work done on SURROUNDINGS)

Question 9

irreversible process

Answer 9

CANNOT be undone by reversing the change to the system (spontan. process is always IRREVERSIBLE)

Question 10

1st law of thermodynamics
Energy (system)+energy (surroundings)=constant

Answer 10

energy cannot be created or destroyed, only transferred

Question 11

Enthalpy

Answer 11

delta H,

Question 12

enthalpy equation (given delta H, want to find H^0f)

Answer 12

delta H^0rxn=ndelta H^0 f(products) -n delta H^0 f (reactants)

Question 13

Reversing the equation changes the

Answer 13

sign of delta H

Question 14

, ΔH alone is
insufficient to determine the
spontaneity of a reaction

Question 15

Processes that result in a
decrease in the energy (ΔH < 0 )
of a system often are
spontaneous

Question 16

Second law of thermodynamics (think of a dirty room)

Answer 16

Energy is dispersed (become
arranged in a more disorderly
way) in any spontaneous
process

Question 17

Entropy (2)

Answer 17

is a measure of
how spread out or disperse
the systems energy is. is a measure of the number of different
configurations that its matter and energy can take

Question 18

For any spontaneous
process,

Answer 18

the entropy of the
universe (system and its
surroundings) must INCREASE

Question 19

Standard Molar Entropy of Formation

Answer 19

S fo
[J/(mol K)]

Question 20

thermodynamic stability

Answer 20

depends on the number of configurations
(microstates) that the components of a system can adopt

Question 21

the most probable state

Answer 21

looks like the state
that has the higher
relative number of
configurations
(microstates)

Question 22

Entropy of a system

Answer 22

is a measure of how dispersed or spread
out its energy is.

Question 23

Intermolecular forces (delta H)

Answer 23

hold molecules
together in liquids and
solids

Question 24

The change in entropy for a system is the difference in entropy

Answer 24

∆Ssys = Sfinal – Sinitial

Question 25

Third law of thermodynamics

Answer 25

states that the entropy of a perfect crystalline substance is zero at absolute zero.

Question 26

Determining the sign of ∆S for a system

Question 27

(molecular compounds) Entropy is affected by

Answer 27

-Single Particle Level (less important) -Molecular Mass -Molecular Complexity (# and types of atoms) -state of matter -number of particles -volume

Question 28

(ionic compunds) entropy is affected by

Answer 28

Ion MASS, CHARGE, and SIZE, states of matter