Chapter 7

Question 1

Isolated system

Answer 1

cant exchange energy or matter with surroundings

Question 2

closed system

Answer 2

can exchange energy, not matter

Question 3

open system

Answer 3

can exchange energy and matter

Question 4

First law of thermodynamics

Answer 4

Delta U= Q-W

U is internal energy
Q is heat added
W is work done

Question 5

isothermal

Answer 5

constant temp, U is constant

Q=W
area is W

Question 6

Adiabatic

Answer 6

No heat exchanged, thermal energy is constant

Q=0, delta U= -Q

change in U= work done on system= opposite work done by

Question 7

isobaric

Answer 7

constant pressure

Area=W

Question 8

isochoric

Answer 8

volumetric, no change in volume, no work

Delta U= Q

no area, no work

Question 9

state function

Answer 9

describes system in equilibrium state

dont describe process, path independent

pressure, density, temp, volume, enthalpy, internal E, gibbs, Entropy

Question 10

process function

Answer 10

describes pathway between equilibrium state

Work and Heat (Q)

Question 11

standard conditions

Answer 11

25 C, 1 atm, 1 M

is most stable state

dont use for ideal gas

Question 12

critical point

Answer 12

where liquid and gas line ends- no distinction between phases

have equal densities

Question 13

Temperature

Answer 13

average KE

as enthalpy increases, temp. increases

Question 14

absolute zero

Answer 14

when one cannot lose anymore thermal energy

Question 15

heat

Answer 15

Q, transfer of energy due to differences in temp.

Question 16

zero law of thermodynamics

Answer 16

when temps are equal, objects are at thermal equilibrium

Question 17

first law of thermodynamics

Answer 17

delta U = Q-W

Question 18

enthalpy

Answer 18

delta H

is Heat (Q) at constant pressure

Question 19

calorimetry

Answer 19

used to measure heat transfer

bomb calorimeter has constant V

Question 20

heat equation

Answer 20

q=mc (delta)t

Question 21

specific heat

Answer 21

amount of energy to raise 1g by 1 C

C of water is 1 cal/gK

Question 22

Heat capacity

Answer 22

MC

Question 23

Why does phase change occur at a constant temp

Answer 23

substance absorbs heat energy and overcomes attractive forces to create a phase change

Question 24

phase change equation

Answer 24

q=ml

L= latent heat

may need to add Q

Question 25

enthalpy

Answer 25

H, heat changes at constant pressure is path independent

Question 26

standard enthalpy of formation

Answer 26

enthalpy to produce 1 mole of compound from its elements in their standard states

Question 27

standard enthalpy of reaction

Answer 27

enthalpy change of reaction at standard conditions

Question 28

Hess Law

Answer 28

enthalpy change of reactions are additive

Question 29

Bond enthalpies

Answer 29

average energy to break a bond in gas phase average of many different compounds is endothermic = H bonds broken- H bonds forms

Question 30

second law of thermodynamics

Answer 30

energy spontaneously disperses from localized to spread out

Question 31

entropy

Answer 31

measure of spontaneous dispersal of energy at a specific temp.- pathway independent delta S= Qrev/T increases when given energy

Question 32

How does entropy in the universe work

Answer 32

change in S universe= S system + S surroundings >0 is always increasing

Question 33

gibbs free energy

Answer 33

Measure of enthalpy and entropy during a process max energy released available to do work Delta g= delta H - T delta S

Question 34

+ S and +H outcome

Answer 34

spontaneous at high T

Question 35

- S and +H outcome

Answer 35

non spontaneous

Question 36

+ S and - H outcome

Answer 36

spontaneous at all temp

Question 37

-S and -H outcome

Answer 37

spontaneous at low temp

Question 38

Delta G reaction standard

Answer 38

= -RTlnKeq greater Keq is more negative delta G

Question 39

delta G reaction not standard

Answer 39

Delta G standard + RTlnQ= RT ln(Q/Keq) if Q > Keq, +ln, + delta G= reverse