[VOCAB] Chapter 6: Thermochemistry: Energy Flow and Chemical Change

Question 1

Biomass Conversion

Answer 1

The process of applying chemical and biological methods to convert plant or animal matter into fuels

Question 2

Calorie (cal)

Answer 2

A unit of energy defined as exactly 4.184 joules; originally defined as the heat needed to raise the temperature of 1 g of water 1°C (from 14.5°C to 15.5°C)

Question 3

Calorimeter

Answer 3

A device used to measure the heat released or absorbed by a physical or chemical process taking place within it

Question 4

Change in Enthalpy (ΔH)

Answer 4

The change in the system’s internal energy plus the product of the constant pressure and the change in volume: ΔH = ΔE + PΔV; alternatively, the heat lost or gained at constant pressure: ΔH = qP

Question 5

Coal Gasification

Answer 5

An industrial process for altering the large molecules in coal to sulfur-free gaseous fuels

Question 6

Endothermic Process

Answer 6

A process that occurs with an absorption of heat from the surroundings and therefore an increase in the enthalpy of the system (ΔH > 0)

Question 7

Enthalpy (H)

Answer 7

A thermodynamic quantity that is equal to the system’s internal energy plus the product of the pressure and volume

Question 8

Enthalpy Diagram

Answer 8

A graphic depiction of the enthalpy change of a system

Question 9

Exothermic Process

Answer 9

A process that occurs with a release of heat to the surroundings and therefore a decrease in the enthalpy of the system (ΔH < 0)

Question 10

Formation Equation

Answer 10

An equation in which 1 mole of a compound forms from its elements

Question 11

Fossil Fuel

Answer 11

Any fuel, including coal, petroleum, and natural gas, derived from the products of the decay of dead organisms

Question 12

Heat (q)

Answer 12

(also thermal energy) The energy transferred between objects because of a difference in their temperatures only

Question 13

Heat Capacity (C)

Answer 13

The quantity of heat required to change the temperature of an object by 1 K

Question 14

Hess’s Law

Answer 14

A law stating that the enthalpy change of an overall process is the sum of the enthalpy changes of the individual steps

Question 15

Internal Energy (E)

Answer 15

The sum of the kinetic and potential energies of all the particles in a system

Question 16

Joule (J)

Answer 16

The SI unit of energy; 1 J = 1 kg · m2/s2

Question 17

Law of Conservation of Energy

Answer 17

(also first law of thermodynamics) A basic observation that the total energy of the universe is constant; thus, ΔEuniverse = ΔEsystem + ΔEsurroundings = 0

Question 18

Methanogenesis

Answer 18

The process of producing methane by anaerobic biodegradation of plant and animal waste

Question 19

Molar Heat Capacity (Cm)

Answer 19

The quantity of heat required to change the temperature of 1 mol of a substance by 1 K

Question 20

Photovoltaic Cell

Answer 20

A device capable of converting light directly into electricity

Question 21

Pressure-Volume Work

Answer 21

(also PV work) A type of mechanical work done when a volume change occurs against an external pressure

Question 22

Specific Heat Capacity (c)

Answer 22

The quantity of heat required to change the temperature of 1 gram of a substance or material by 1 K

Question 23

Standard Enthalpy of Formation

Answer 23

(also standard heat of formation) The enthalpy change occurring when 1 mol of a compound forms from its elements with all components in their standard states

Question 24

Standard Enthalpy of Reaction

Answer 24

(also standard heat of reaction) The enthalpy change that occurs during a reaction when all components are in their standard states

Question 25

Standard State

Answer 25

A set of specific conditions used to compare thermodynamic data: 1 atm for gases behaving ideally, 1 M for dissolved species, or the pure substance for liquids and solids

Question 26

State Function

Answer 26

A property of a system determined only by the system’s current state, regardless of how it arrived at that state

Question 27

Surroundings

Answer 27

All parts of the universe other than the system being considered

Question 28

System

Answer 28

The defined part of the universe under study

Question 29

Thermochemical Equation

Answer 29

A balanced chemical equation that includes the enthalpy change for the reaction

Question 30

Thermochemistry

Answer 30

The branch of thermodynamics that focuses on the heat involved in chemical and physical change

Question 31

Thermodynamics

Answer 31

The study of energy and its transformations

Question 32

Work (w)

Answer 32

The energy transferred when an object is moved by a force