Chemistry Chapter 7: Thermochemistry (2 Stars)

Question 1

Systems are classified based on what is or is not _______ with the surroundings.

Answer 1

exchanged

Question 2

________ exchange neither matter nor energy with the environment.

Answer 2

Isolated systems

Question 3

Closed systems ____ exchange energy but not matter with the environment.

Answer 3

can

Question 4

_______ can exchange both energy and matter with the environment.

Answer 4

Open systems

Question 5

_______ processes occur at a constant temperature.

Answer 5

Isothermal

Question 6

________ exchange no heat with the environment.

When Q = 0, the first law simplifies to ΔU = –W

Answer 6

Adiabatic

Question 7

_______ processes occur at a constant pressure.

Answer 7

Isobaric

Question 8

Isovolumetric (isochoric) processes occur at a _______ volume.

Answer 8

constant

Question 9

State functions describe the physical properties of an equilibrium state; they are pathway _______ and include pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, and entropy.

Answer 9

independent

Question 10

Standard conditions are defined as ____ K, 1 atm, and 1 M concentrations.

Answer 10

298 K

Question 11

The standard state of an element is its most prevalent form under standard conditions; standard enthalpy, standard entropy, and standard ______ are all calculated under standard conditions.

Answer 11

free energy

Question 12

Phase changes exist at characteristic temperatures and ______.

Answer 12

pressures.

Question 13

Fusion (melting) and freezing (crystallization or solidification) occur at the boundary between the solid and the _____ phases.

Answer 13

liquid

Question 14

Vaporization (evaporation or boiling) and _______ occur at the boundary between the liquid and the gas phases.

Answer 14

condensation

Question 15

Sublimation and deposition occur at the boundary between the solid and ____ phases.

Answer 15

gas

Question 16

At temperatures above the critical point, the liquid and gas phases are ________.

Answer 16

indistinguishable

Question 17

At the triple point, all three phases of matter exist in ________

Answer 17

equilibrium.

Question 18

The phase diagram for a system graphs the phases and phase equilibria as a function of ______ and pressure.

Answer 18

temperature

Question 19

Temperature and heat are/are not the same thing.

Answer 19

are not

Question 20

Temperature is a scaled measure of the average ______ energy of a substance.

Answer 20

kinetic

Question 21

_____ is the transfer of energy that results from differences of temperature between two substances.

Answer 21

Heat

Question 22

The heat content of a system undergoing heating, cooling, or phase changes is the ____ of all the respective energy changes.

Answer 22

sum

Question 23

_______ is a measure of the potential energy of a system found in intermolecular attractions and chemical bonds.

Answer 23

Enthalpy

Question 24

Hess’s law states that the total change in potential energy of a system is equal to the changes of potential energies of the _____ steps of the process.

Answer 24

individual

Question 25

_____ can also be calculated using heats of formation, heats of combustion, or bond dissociation energies.

Answer 25

Enthalpy

Question 26

Entropy, while often thought of as disorder, is a measure of the degree to which energy has been spread throughout a system or ______ a system and its surroundings.

Answer 26

between

Question 27

Entropy is a ratio of heat transferred per mole per unit _____

Answer 27

kelvin.

Question 28

Entropy is maximized at ________

Answer 28

equilibrium

Question 29

Gibbs free energy is derived from both _____ and entropy values for a given system.

Answer 29

enthalpy

Question 30

The change in _______ determines whether a process is spontaneous or nonspontaneous.

Answer 30

Gibbs free energy

Question 31

ΔG < 0: reaction proceeds in _____direction (spontaneous)

Answer 31

forward

Question 32

ΔG = 0: reaction is in _______

Answer 32

dynamic equilibrium

Question 33

ΔG _ 0: reaction proceeds in reverse direction (nonspontaneous)

Answer 33

>

Question 34

_______ depends on temperature; temperature-dependent processes change between spontaneous and nonspontaneous,

Answer 34

Gibbs free energy

Question 35

ΔU = Q – W

Define

Answer 35

where ΔU is the change in internal energy of the system, Q is the heat added to the
system, and W is the work done by the system.

Question 36

Exergonic or Endogonic?

Answer 36

Question 37

Exergonic or Endogonic?

Answer 37

Question 38

Fill in the blanks

Answer 38

Question 39

Idenify the missing items

Answer 39