6.1-2

Question 1

true or false: all chemical reactions involve energy changes

Answer 1

true

Question 2

area of chemistry dealing with applying thermodynamics principles to energy changes in chemical reactions

Answer 2

chemical thermodynamics

Question 3

ability to do work and change matter

Answer 3

energy

Question 4

law stating that energy can neither be created nor destroyed

Answer 4

law of conservation of energy

Question 5

energy of motion

Answer 5

kinetic energy

Question 6

energy associated with the position of an object and the forces acting upon it

Answer 6

potential energy

Question 7

the portion of the universe or the sample of matter being studied

Answer 7

system

Question 8

everything in the universe outside the system

Answer 8

surroundings

Question 9

sum of all the possible forms of energy of the ions, atoms, and molecules in a system

Answer 9

internal energy (E)

Question 10

thermodynamic property whose value is determined only by the state of the system

Answer 10

state function

Question 11

true or false: internal energy is independent of the path taken to reach a particular state and of the system’s history

Answer 11

true

Question 12

law stating that the energy gained (or lost) by a system equals the energy lost (or gained) by the surroundings

Answer 12

first law of thermodynamics

Question 13

transfer of energy as a result of a temperature difference

Answer 13

heat (Q)

Question 14

transfer of energy through a force applied across a distance

Answer 14

work (W)

Question 15

change in energy formula

Answer 15

ΔE = Q + W (change in energy = heat + work)

Question 16

if internal energy increases, is ΔE positive or negative?

Answer 16

positive

Question 17

if internal energy decreases, is ΔE positive or negative?

Answer 17

negative

Question 18

unit of energy and energy transfer

Answer 18

Joule (J)

Question 19

1 cal = how many Joules?

Answer 19

4.184 J

Question 20

internal energy plus the product of pressure and volume

Answer 20

enthalpy (H)

Question 21

enthalpy formula

Answer 21

H = E + PV

Question 22

_______ describes a process in which energy is absorbed

Answer 22

endothermic

Question 23

enthalpy increases in _______

Answer 23

endothermic reactions

Question 24

heat is a reactant in an _________ reaction

Answer 24

endothermic

Question 25

________ describes a process in which energy is released

Answer 25

exothermic

Question 26

enthalpy decreases in _________

Answer 26

exothermic

Question 27

heat is a product in an __________ reaction

Answer 27

exothermic reaction

Question 28

in an endothermic reaction, ΔH is _______

Answer 28

positive

Question 29

in an exothermic reaction, ΔH is _______

Answer 29

negative

Question 30

total energy released or absorbed between the start of a reaction and its end

Answer 30

enthalpy of reaction (ΔH)

Question 31

chemical equation written to show the change in enthalpy

Answer 31

thermochemical equation

Question 32

normal physical state of an element at 100 kPa and a specified temperature

Answer 32

standard state (25 degrees Celsius is what we will use)

Question 33

true or false: any element in its standard state at the specified temperature has an assigned enthalpy of zero

Answer 33

true

Question 34

enthalpy change for a reaction in which 1 mol of a compound is formed from its elements in their standard states

Answer 34

Standard enthalpy of formation (ΔfH°)

Question 35

law stating that when a series of reactions occurs, the enthalpy of the net (overall) reaction is the sum of the individual reactions’ enthalpies

Answer 35

Hess's law