Test 13

Question 1

The branch of science that studies the transfer of energy during chemical reactions or phase changes

Answer 1

Thermochemistry

Question 2

Expresses the average kinetic energy in the particles of a sample

Answer 2

Temperature

Question 3

An insulated container, similar to a thermos, in which a thermometer detects the enthalpy that occurs during a chemical reaction

Answer 3

Calorimeter

Question 4

The heat that produces a phase change

Answer 4

Latent heat

Question 5

The heat that produces a temperature change in the substance when applied

Answer 5

Sensible heat

Question 6

Why do enthalpies of vaporization differ widely?

Answer 6

The strength of intermolecular attractions in different liquids vary

Higher value means stronger intermolecular attractions

Question 7

The amount of thermal energy required to raise the temperature of 1 g of the substance by 1°C

Answer 7

Specific heat Csp

Question 8

Substances with__specific heats require large amounts of energy for a given temperature change and will change temperature only slowly

Answer 8

High

Question 9

Which retains heat longer, substances with high specific heat values or low specific heat values?

Answer 9

High specific heat values

Question 10

Why do the products in an exothermic reaction have a lower enthalpy than the reactants

Answer 10

Because energy is released during the reaction

Question 11

If the reaction is endothermic the energy will be a

Answer 11

Reactant

Question 12

If the reaction is exothermic the energy will be a

Answer 12

Product

Question 13

A negative enthalpy of reaction value signifies what kind of reaction?

Answer 13

Exothermic

Question 14

The enthalpy of reaction of a reverse reaction has the__magnitude but the__sign of the delta H of the forward reaction

Answer 14

Same

Opposite

Question 15

The enthalpy change for the reaction that produces one mole of a compound in its standard state from its elements in their standard states

Answer 15

Standard molar enthalpy of formation /\ H °f

Question 16

What does the degree symbol of /\ H °f mean?

Answer 16

It signifies that this delta H refers to standard conditions

Question 17

Energy released as heat by the complete burning of one mole of a substance at standard conditions

Answer 17

Standard molar enthalpy of combustion /\ H °c

Question 18

r States that the enthalpy change of a reaction equals the sum of the enthalpy changes for each step of the process

Answer 18

Hess’s Law

Question 19

What is always required to break bonds

Answer 19

Energy

Question 20

Entropy measures

Answer 20

Randomness of a system

Question 21

Entropy __as temperature increases

Answer 21

Increases

Question 22

Delta H represents

Answer 22

Enthalpy

Question 23

Delta S represents

Answer 23

Entropy

Question 24

What is the formula for calculating free energy change (/\ G)

Answer 24

/\G=/\H-T/\S

Question 25

What does a negative G indicate

Answer 25

A decline in free energy and it signifies that a reaction may occur spontaneously The reaction is favorable

Question 26

J to KJ

Answer 26

Move decimal three places to the left

Question 27

KJ to J

Answer 27

move decimal three places to the right

Question 28

Must convert from

Answer 28

Celsius to Kelvin

Question 29

Formula for Celsius to Kelvin

Answer 29

°C + 273 = K

Question 30

Why does drink stay hot longer than pop tart

Answer 30

Water has a higher specific heat than a pop tart

Question 31

When determining free energy change the temperature must be in

Answer 31

K

Question 32

Symbol for free energy

Answer 32

G

Question 33

G measures

Answer 33

Favorability of reactions considering both entropy and enthalpy

Question 34

And spontaneous natural processes entropy tends to__and enthalpy __

Answer 34

Increases Decreases

Question 35

If it's going from weaker bonds to stronger bonds, it is

Answer 35

Exothermic

Question 36

Gas has the__entropy

Answer 36

Most

Question 37

Formula for /\H°reaction

Answer 37

/\H°reaction= E /\H products- E /\H reactants

Question 38

Formula for /\S°reaction

Answer 38

/\S°reaction= E /\S products- E /\S reactants

Question 39

Used to determine whether increase or decrease in entropy

Answer 39

Formula for /\S

Question 40

Formula for /\G

Answer 40

/\G= /\H- T /\S

Question 41

/\H- /\S+

Answer 41

/\G - always

Question 42

/\H- /\S-

Answer 42

/\G- at low temperatures

Question 43

/\H+ /\S+

Answer 43

/\G - at high temperatures

Question 44

/\H+ /\S-

Answer 44

/\G + always

Question 45

The measure of the dispersal of energy in a system; the net decrease of usable energy in the system for a given temperature and quantity of matter

Answer 45

Entropy S

Question 46

-/\H=

Answer 46

Exothermic

Question 47

+/\H=

Answer 47

Endothermic

Question 48

-/\S=

Answer 48

Decrease in entropy

Question 49

+/\S=

Answer 49

Increase in entropy

Question 50

The quantity of thermal energy required to convert one mole of a liquid at its boiling point to its vapor at the same temperature

Answer 50

Molar enthalpy of vaporization /\H vap

Question 51

A chemical equation that shows the reactants, products, and amount of energy that is released or absorbed as heat

Answer 51

Thermochemical equation

Question 52

Standard state

Answer 52

25°C (298 K), and one atm of pressure