Ch 7: Thermochemistry

Question 1

isolated system

Answer 1

exchange neither matter nor energy with the environment

Question 2

closed system

Answer 2

exchange energy but not matter with the environment

Question 3

open system

Answer 3

exchange both energy and matter with the environment

Question 4

isothermal

Answer 4

processes occur at a constant temperature

Question 5

adiabatic

Answer 5

processes exchange no heat with the environment

Question 6

isobaric

Answer 6

processes occur at a constant rate

Question 7

isovolumetric (isochoric)

Answer 7

processes occur at a constant volume

Question 8

state functions

Answer 8

describe physical properties of an equilibrium state; pathway independent

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

under PRESSURE feeling DENSE, i want HUGS and TV

Question 9

standard conditions

Answer 9

298K
1 atm
1 M conc

Question 10

standard state of an element is prevalent under standard conditions

Answer 10

stand enthalpy, stand entropy, stand free energy

Question 11

phase changes exist at

Answer 11

characteristic pressure and temperatures

Question 12

fusion is ___ and freezing is ___ occur btw solid and liquid phases

Answer 12

melting

crystallization or solidification

Question 13

vaporization _____ and condensation occur btw liq and gas

Answer 13

evaporation or boiling

Question 14

occur at boundary btw solid and gas phase

Answer 14

sublimation and deposition

Question 15

at temps above the _____ liq and gas phases are indistinguishable

Answer 15

critical point

Question 16

at the ____ all 3 phases of matter exist in equilibrium

Answer 16

triple point

Question 17

temperature

Answer 17

scaled measure of average kinetic energy of a substance

Question 18

heat

Answer 18

transfer of energy that results from difference of temperature between two substances

Question 19

enthalpy

Answer 19

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

Question 20

hess’s law

Answer 20

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

Question 21

can be calculated using heat of formation, heats of combustion, or bond dissociation energies

Answer 21

enthalpy

Question 22

entropy

Answer 22

often thought of as disorder, measure of degree to which energy has been spread throughout a system or between a system and its surroundings

ratio of heat transferred per mole per unit kelvin

maximized at equilibrium

Question 23

gibbs free energy

Answer 23

derived from both enthalpy and entropy and determines if process is spontaneous or non-spontaneous

depends on temperature; temp dep processes change btw spontaneous and nonspontaneous depending on the temp