Thermochemistry

Question 1

Thermochemistry

Answer 1

Study of measuring the amount of heat absorbed or released during a chemical reaction or a physical change

Question 2

Energy

Answer 2

Capacity to supply heat or do work

Question 3

Work (w)

Answer 3

Energy transfer due to changes in external, macroscopic variables such as pressure and volume; or causing matter to move against an opposing force

Question 4

Potential Energy

Answer 4

Energy of a particle or system of particles derived from relative position

Question 5

Kinetic Energy

Answer 5

Energy of a moving body, in joules, equal to 1/2mv^2 (where m = mass and v = velocity)

Question 6

Thermal Energy

Answer 6

Kinetic energy associated with the random motion of atoms and molecules

Question 7

Temperature

Answer 7

Intensive property of matter that is in a quantitative measure of “hotness” and “coldness”

Question 8

Heat (q)

Answer 8

Transfer of thermal energy between two bodies

Question 9

Exothermic Process

Answer 9

Chemical reaction or physical change that releases heat

Question 10

Endothermic Process

Answer 10

Chemical reaction or physical change that absorbs heat

Question 11

Calories (cal)

Answer 11

Unit of heat or other energy; the amount of energy required to raise 1 gram of water by 1 degree Celsius; 1 cal is defined as 4.184 J

Question 12

Joule (J)

Answer 12

SI unit of energy; 1 joule is the kinetic energy of an object with a mass of 2 kilograms moving with a velocity of 1 meter per second, 1 J = 1 kg m^2/s and 4.184 J = 1 cal

Question 13

Heat Capacity

Answer 13

Extensive property of a body of matter that represents the quantity of heat required to increase its temperature by 1 degree Celsius (or 1 kelvin)

Question 14

Specific Heat Capacity (c)

Answer 14

Intensive property of a substance that represents the quantity of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius (or 1 kelvin)

Question 15

Calorimetry

Answer 15

Process of measuring the amount of heat involved in a chemical or physical process

Question 16

System

Answer 16

Portion of matter undergoing a chemical or physical change being studied

Question 17

Surroundings

Answer 17

All matter other than the system being studied

Question 18

Calorimeter

Answer 18

Device used to measure the amount of heat absorbed or released in a chemical or physical process

Question 19

Bomb Calorimeter

Answer 19

Device designed to measure the energy change for processes occurring under conditions of constant volume; commonly used for reactions involving solid and gaseous reactants or products

Question 20

Nutritional Calorie (Calorie)

Answer 20

Unit used for quantifying energy provided by digestion of foods, defined as 1000 cal or 1 kcal

Question 21

Chemical Thermodynamics

Answer 21

Area of science that deals with the relationships between heat, work, and all forms of energy associated with chemical and physical processes

Question 22

Internal Energy (U)

Answer 22

Total of all possible kinds of energy present in a substance or substances

Question 23

First Law of Thermodynamics

Answer 23

Internal energy of a system changes due to heat flow in or out of the system or work done on or by the system

Question 24

Expansion Work (Pressure-Volume Work)

Answer 24

Work done as a system expands or contracts against external pressure

Question 25

State Function

Answer 25

Property depending only on the state of a system, and not the path taken to reach that state

Question 26

Enthalpy (H)

Answer 26

Sum of a system’s internal energy and the mathematical product of its pressure and volume

Question 27

Enthalpy Change (deltaH)

Answer 27

Heat released or absorbed by a system under constant pressure during a chemical or physical process

Question 28

Standard State

Answer 28

Set of physical conditions as accepted as common reference conditions for reporting thermodynamic properties; 1 bar of pressure, and solutions at 1 molar concentrations, usually at a temperature of 298.15 K

Question 29

Standard Enthalpy of Combustion (deltaH*C)

Answer 29

Heat released when one mole of a compound undergoes complete combustion under standard conditions

Question 30

Hydrocarbons

Answer 30

Compound composed only of hydrogen and carbon; the major component of fossil fuels

Question 31

Standard Enthalpy of Formation (deltaH*f)

Answer 31

Enthalpy change of a chemical reaction in which 1 mole of a pure substance is formed from its elements in their most stable states under standard state conditions

Question 32

Hess’s Law

Answer 32

If a process can be represented as the sum of several steps, the enthalpy change of the process equals the sum of the enthalpy changes of the steps