Chapter 6: Thermochemistry

Question 1

Calorimetry

Answer 1

The measurement of heat changes

Question 2

Chemical Energy

Answer 2

energy stored within the structural units of chemical substances

Question 3

Closed System

Answer 3

A system that enables the exchange of energy but not mass with its surroundings

Question 4

Endothermic Process

Answer 4

Processes that absorb heat from the surroundings

Question 5

Energy

Answer 5

the capacity to do work or produce change

Question 6

Enthalpy (H)

Answer 6

a thermodynamic quantity used to describe heat changes taking place at constant pressure

Question 7

Enthalpy of reaction

Answer 7

the difference between the enthalpies of the products and the enthalpies of the reactants

Question 8

enthalpy of solution

Answer 8

the heat generated or absorbed when a certain amount of solute is dissolved in a certain amount of solvent

Question 9

exothermic process

Answer 9

processes that give off heat to surroundings

Question 10

First Law of Thermodynamics

Answer 10

energy can be converted from one form to another, but cannot be created nor destroyed

Question 11

Heat

Answer 11

transfer of energy between two bodies that are at different temperatures

Question 12

Heat Capacity

Answer 12

the amount of heat required to raise the temperature of a given quantity of the substance by one degree C

Question 13

Heat of dilution

Answer 13

the heat change associated with the dilution process

Question 14

Heat of hydration

Answer 14

the heat change associated with the hydration process

Question 15

Heat of solution

Answer 15

same as enthalpy of solution

Question 16

Hess’s Law

Answer 16

When reactants are converted to products, the change in enthalpy is the same whether the reaction takes place in one step or in a series of steps

Question 17

Isolated System

Answer 17

A system that does not allow the transfer of either mass or energy to or from its surroundings

Question 18

Lattice Energy (U)

Answer 18

The energy required to completely separate one mole of a solid ionic compound into gaseous ions

Question 19

Law of Conservation of energy

Answer 19

the total quantity of energy in the universe is constant

Question 20

Open system

Answer 20

a system that can exchange mass and energy with its surroundings

Question 21

Potential energy

Answer 21

energy available by virtue of an object’s position

Question 22

Radiant energy

Answer 22

energy transmitted in the form of waves

Question 23

Specific Heat (s)

Answer 23

The amount of heat energy required to raise the temp of one gram of a substance by one degree C

Question 24

Standard enthalpy of formation

Answer 24

The heat change that results when one mole of a compound is formed from its elements in their standard states

Question 25

Standard enthalpy of reaction

Answer 25

The enthalpy change when the reaction is carried out under standard-state conditions

Question 26

Standard State

Answer 26

The condition of 1 atm of pressure

Question 27

State function

Answer 27

a property that is determined by the state of the system

Question 28

State of a system

Answer 28

The values of all pertinent macroscopic variables of a system

Question 29

Surroundings

Answer 29

The rest of a universe outside of a system

Question 30

System

Answer 30

Any specific part of the universe that is of interest to us

Question 31

Thermal Energy

Answer 31

Energy associated with the random motion of atoms and molecules

Question 32

Thermochemical equation

Answer 32

an equation that shows both the mass an enthalpy relations

Question 33

thermochemistry

Answer 33

the study of heat changes in chemical reactions

Question 34

thermodynamics

Answer 34

the scientific study of the interconversion of heat and other forms of energy

Question 35

work

Answer 35

directed energy change resulting from a process