OpenStax Chapter 5 Key Terms

Question 1

thermochemistry

Answer 1

study of the heat absorbed or released during chemical and physical changes

Question 2

work

Answer 2

process of causing matter to move against an opposing force

Question 3

potential energy

Answer 3

the energy that an object has because of its relative position, composition, or condition

Question 4

kinetic energy

Answer 4

energy that an object possesses because of its motion

Question 5

thermal energy

Answer 5

kinetic energy
associated with the random motion of atoms and molecules

Question 6

exothermic process

Answer 6

releases heat
system gets colder, surroundings get warmer

Question 7

endothermic process

Answer 7

absorbs heat
system gets warmer, surroundings get colder

Question 8

temperature

Answer 8

quantitative measure of “hot” or “cold”
K, C, F

Question 9

calorie

Answer 9

amount of energy required to increase the temperature of one gram of water 1 C

Question 10

joule

Answer 10

amount of energy used when a force of 1 N moves an object one meter

Question 11

heat capacity

Answer 11

quantity of heat (q) absorbed or released by a body of matter when it experiences a temperature change of 1 C
extensive

Question 12

specific heat

Answer 12

quantity of heat required to raise 1 gram of a substance by 1 C
intensive

Question 13

molar heat capacity

Answer 13

quantity of heat required to raise 1 mol of a substance by 1 C

Question 14

calorimetry

Answer 14

method for measuring the amount o heat transferred to or from a substance

Question 15

system

Answer 15

the substance or substances undergoing the chemical or physical change

Question 16

surroundings

Answer 16

all other matter, including components of the measurement apparatus, that serve to either provide heat to the system or absorb heat from the system

Question 17

chemical thermodynamics

Answer 17

study of the relationship between heat, work, and other forms of energy involved in the

Question 18

internal energy

Answer 18

state function
energy associated with particles of the substance
depends on the state of the system
U = q + w

Question 19

expansion/pressure-volume work

Answer 19

expansion work
P𝚫V=-w
if work is done on the system, 𝚫V = -
if work is done by the system 𝚫V = +

Question 20

state function

Answer 20

depends only on the state of the system and not how the state is reached

Question 21

enthalpy

Answer 21

sum of the system’s internal energy (U) and the system’s pressure-volume work
H = U + PV
cannot be directly measured, so instead measure the change in enthalpy at constant pressure
extensive

Question 22

standard state conditions

Answer 22

1 atm, 1 M, 25 C

Question 23

enthalpy of combustion

Answer 23

enthalpy change when one mole of a substance burns under standard state conditions
reactants - products

Question 24

enthalpy of formation

Answer 24

enthalpy change for a reaction in which exactly one mole of a pure substance formed from free elements in their most stable form under standard state conditions

Question 25

Hess’s Law

Answer 25

if a process can be written as a sum of the several stepwise steps, the enthalpy change of the total process equals the sum of the enthalpy changes of the steps

Question 26

heat of reaction

Answer 26

equal to the enthalpy under constant pressure