Chapter 7: Thermochemistry

Question 1

what is an isolated system

Answer 1

exchange neither matter nor energy with environmentw

Question 2

what is a closed system

Answer 2

exchange energy but not matter

Question 3

what is an open system

Answer 3

exchange both energy and matter

Question 4

what is an isothermal process

Answer 4

constant temperature

Question 5

what is an adiabatic process

Answer 5

exchange no heat with the environment

Question 6

what is an isovolumetric process

Answer 6

constant volume

Question 6

what is an isobaric process

Answer 6

constant pressure

Question 7

what are state functions

Answer 7

describe physical properties of an equilibrium state and are pathway independent

Question 8

what are THE state functions

Answer 8

pressure, density, temp, volume, enthalpy, internal energy, entropy, gibbs free energy

Question 9

what are standard conditions

Answer 9

298 K 1 atm 1 M

Question 10

what is fusion

Answer 10

melting from solid to liquid

Question 11

what is freezing

Answer 11

from liquid to solid

Question 12

what is vaporization

Answer 12

liquid to gas

Question 13

what is condensation

Answer 13

gas to liquid

Question 14

what is sublimation

Answer 14

solid to gas

Question 15

what is deposition

Answer 15

gas to solid

Question 16

what is the critical point

Answer 16

temperatures above critical point liquid and gas phases are indistinguishable

Question 17

what is the triple point

Answer 17

all three phases of matter exist in equilibrium

Question 18

what is temperature

Answer 18

scaled measure of average kinetic energy of a substane

Question 19

what is heat

Answer 19

transfer of energy that results from difference of temperature

Question 20

what is enthalpy

Answer 20

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

Question 21

what is Hess’s law

Answer 21

states that total change in potential energy is equal to the changes in potential energies of individual steps of the process

Question 22

how can you calculate enthalpy

Answer 22

heats of formation, bond dissociation energy, heat of combustion

Question 23

what is entropy

Answer 23

measure of the degree to which energy has been spread throughout a system

Question 24

what is the ratio of entropy

Answer 24

heat transferred /1 mole/ 1 K

Question 25

when is entropy max

Answer 25

at equilibrium

Question 26

what is gibbs free energy

Answer 26

derived from enthalpy and entropy; dependent on temp

Question 27

equation for first law of thermodynamics

Answer 27

U = Q - W

Question 28

Equation for heat transfer

Answer 28

q = mc(delta T)

Question 29

Equation of heat transfer during. phase change

Answer 29

q = mL

Question 30

Equation for enthalpy of reaction

Answer 30

delta H = H prod. - H react.

Question 31

equation for entropy

Answer 31

S = Qrev / T

Question 32

Equation for second law of thermo.

Answer 32

delta S = S system + S surround

Question 33

Equation for standard entropy of reaction

Answer 33

delta S = (sum of) S prod. - (sum of) S react.

Question 34

equation for Gibbs

Answer 34

delta G = Delta H - T(delta S)

Question 35

Equation for gibbs using Keq

Answer 35

-RTln(keq)

Question 36

Equation for gibbs using Q

Answer 36

RT ln ( Q/Keq)