DAT Gen Chem Thermodynamics and Thermochemistry

Question 1

that energy cannot be created or destroyed. what law

Answer 1

first law of thermodynamics, or law of conservation of energy

Question 2

the chemical reaction
containing reactants and products

Answer 2

systhem

Question 3

the environment that
surrounds the system

Answer 3

surroundings

Question 4

the sum of the system and
its surroundings

Answer 4

universe

Question 5

heat being
transferred from the surroundings into the
system, making the change in enthalpy for the
system greater than 0 (∆H > 0).

Answer 5

endothermic

Question 6

heat being transferred from the system to the
surroundings, making the change in enthalpy
for the system less than 0 (∆H < 0)

Answer 6

exothermic

Question 7

amount of heat
energy contained within a system.

Answer 7

enthalpy

Question 8

endothermic phase changes

Answer 8

sublimation, vaporization, melting

Question 9

exothermic phase changes

Answer 9

deposition, condensation, freezing

Question 10

transfer of heat via direct
contact.

Answer 10

conduction

Question 11

exist in
liquids or gases when hotter, less dense
areas rise, and the cooler, more dense areas
sink.

Answer 11

convection

Question 12

transfer of heat via
electromagnetic…

Answer 12

radiation

Question 13

change in internal energy =

Answer 13

heat + work

Question 14

work =

Answer 14

• Pressure x change in volume

Question 15

When there is an increase in volume (ΔV > 0),
work is WHAT the system.

Answer 15

done by, negative work

Question 16

positive q value

Answer 16

endothermic

Question 17

negative q value

Answer 17

exothermic

Question 18

positive work value

Answer 18

compression

Question 19

negative work value

Answer 19

expansion

Question 20

defined by the
amount of energy required to raise the
temperature of 1.0 gram of a substance by
1°Celsius.

Answer 20

specific heat capacity

Question 21

the specific heat
capacity for the same molecule differs
depending on…

Answer 21

the molecular state

Question 22

(no phase change) heat absorbed or released by substance =

Answer 22

mass x specific heat capacity x delta T

Question 23

(phase change) heat absorbed or released by substance =

Answer 23

mass of substance (kg) x heat of fusion/vap

Question 24

heat required to change a
substance from liquid to gas.

Answer 24

heat of vaporization

Question 25

heat required to change a substance from solid
to liquid.

Answer 25

heat of fusion

Question 26

heat of reaction =

Answer 26

• heat of calorimeter

Question 27

heat of calorimeter =

Answer 27

heat capacity of calorimeter x change in temp

Question 28

a property that
depends only on the initial and final state of the
system, and is independent of the path taken.

Answer 28

state function

Question 29

describes the amount of disorder/
randomness of a system.

Answer 29

entropy

Question 30

what kind of reaction is favored

Answer 30

exothermic

Question 31

which is more stable, hi entropy or low

Answer 31

high

Question 32

states that
the entropy of the universe is always increasing.

Answer 32

second law of thermodynamics

Question 33

states that
the entropy of a pure crystalline substance at
absolute zero temperature (0 Kelvin) is zero.

Answer 33

third law of thermodynamics

Question 34

∆Srxn > 0 - reaction is

Answer 34

entropically favorable;
products are more disordered than the
reactants.

Question 35

as dissolution increases, what happens to entropy

Answer 35

increases

Question 36

criteria for
spontaneity, and it depends on entropy (∆S),
enthalpy (∆H), and temperature.

Answer 36

Gibbs Free Energy (∆G)

Question 37

delt g =

Answer 37

delt h - (temp x delt s)

Question 38

∆G < 0

Answer 38

spontaneous rxn

Question 39

∆G > 0

Answer 39

nonspontaneous

Question 40

if delt g is negative, what is k value

Answer 40

above 1

Question 41

if delt g is positive, what is k value

Answer 41

less than one