chapter 5 review

Question 1

system

Answer 1

the part of the universe chosen to study

Question 2

surroundings

Answer 2

the rest of the universe

Question 3

open systems

Answer 3

freely exchanges energy AND matter with its surroundings

Question 4

closed system

Answer 4

can exchange energy, but NOT matter with is surroundings

Question 5

isolated system

Answer 5

cannot exchange energy OR matter with its surroundings

Question 6

kinetic energy

Answer 6

the energy of a MOVING object (includes thermal energy-molecular motion)

Question 7

potential energy

Answer 7

energy resulting from condition, position, or composition (includes chemical energy- potential energy stored in bonds)

Question 8

the first law of thermodynamics

Answer 8

energy can be converted from one form to another, but cannot be created or destroyed

Question 9

internal energy of a system (U or E)

Answer 9

sum of all the potential and kinetic energies in the system

Question 10

ΔU=

Answer 10

q (heat) + w (work)

Question 11

ΔU isolated=

Answer 11

0

Question 12

ΔU system =

Answer 12

-ΔU surroundings

Question 13

system to surroundings

Answer 13

q and w (-)

Question 14

surroundings to system

Answer 14

q and w (+)

Question 15

heat

Answer 15

the transfer of thermal energy between a system and surroundings due to temperature difference

Question 16

1 cal=

Answer 16

4.184 J

Question 17

(P-V) pressure-volume work

Answer 17

work involved in the expansion or compression of gas

Question 18

w (work)=

Answer 18

-PextΔV
negative external pressure times the change in volume

Question 19

how can you tell if P-V work has happened

Answer 19

conceptually= change of gas in a chemical reaction
ex) 2C2H6(s) + 7O2(g) —> 6H2O(l) + 4CO2 (g)
there were 7 moles of gas and then it became four moles of gas
visually= the piston moves

Question 20

heat capacity(C)=

Answer 20

q/ΔT

Question 21

q=

Answer 21

mcΔT

Question 22

solid to liquid

Answer 22

melting or fusion

Question 23

liquid to gas

Answer 23

evaporation or vaporization

Question 24

enthalpy(H)

Answer 24

the change in the energy of a system at constant pressure, sum of the change in internal energy and the P-V product

Question 25

ΔH=

Answer 25

ΔU + PΔV

Question 26

enthalpy is positive in an

Answer 26

endothermic reaction

Question 27

enthalpy is negative in an

Answer 27

exothermic reaction

Question 28

simple calorimeter

Answer 28

coffee cup
constant pressure

Question 29

complex calorimeter

Answer 29

bomb calorimeter
constant volume

Question 30

qcombustion=

Answer 30

qreaction (qrxn)

Question 31

qcalorimeter=

Answer 31

-qrxn

Question 32

qcal=

Answer 32

CcalΔT
heat capacity times the change in temp

Question 33

standard enthalpy of formation (ΔHf)=

Answer 33

sum of products minus sum of reactants

Question 34

standard state for C

Answer 34

solid graphite

Question 35

standard state for H2

Answer 35

gas

Question 36

standard state for I2

Answer 36

solid

Question 37

standard state for S8

Answer 37

solid

Question 38

standard state for Br2

Answer 38

liquid

Question 39

standard state for cl2

Answer 39

gas

Question 40

system releases energy

Answer 40

sign is negative

Question 41

work done ON system

Answer 41

positive

Question 42

work done BY a system

Answer 42

negative

Question 43

lower specific heat

Answer 43

open to change in temp, takes less energy

Question 44

higher specific heat

Answer 44

more resistant to change in temp, requires more energy