SCH4U - Thermochemistry

Question 1

Thermochemistry:

Answer 1

the study of the energy changes that accompany physical or
chemical changes in matter.

Question 2

Energy:

Answer 2

the ability to do work; SI units joules (J).

Question 3

Work:

Answer 3

the amount of energy transferred by a force over a distance; SI units joules (J).

Question 4

Potential Energy (PE or Ep):

Answer 4

the energy of a body or system due to its position or
composition.

Question 5

Kinetic Energy (KE or Ek):

Answer 5

the energy of an object due to its motion.

Question 6

Thermal Energy (q):

Answer 6

the total quantity of kinetic and potential energy in a substance.

Question 7

Heat:

Answer 7

the transfer of thermal energy from a warm object to a cooler object.

Question 8

Temperature:

Answer 8

a measure of the average kinetic energy of entities in a substance.

Question 9

Chemical System:

Answer 9

a group of reactants and products being studied.

Question 10

Surroundings:

Answer 10

all the matter that is not part of the system.

Question 11

Open System:

Answer 11

a system in which both matter and energy are free to enter and leave the
system.

Question 12

Closed System:

Answer 12

a system in which energy can enter and leave the system, but matter
cannot.

Question 13

Isolated System:

Answer 13

an ideal system in which neither matter nor energy can move in or out.

Question 14

Endothermic:

Answer 14

absorbing energy from the surroundings.

Question 15

Exothermic:

Answer 15

releasing energy to the surroundings.

Question 16

Fission:

Answer 16

the process of using a neutron to split a nucleus of high atomic mass into two
nuclei with smaller masses.

Question 17

Fusion:

Answer 17

the process of combining two or more nuclei of low atomic mass to form a
heavier, more stable nucleus.

Question 18

Specific Heat Capacity (c):

Answer 18

the quantity of thermal energy required to raise the
temperature of 1 g of a substance by 1 °C; SI units J/(g∙°C).

Question 19

Calorimetry:

Answer 19

the experimental process of measuring the thermal energy change in a
chemical or physical change.

Question 20

Calorimeter:

Answer 20

a device that is used to measure thermal energy changes in a chemical or
physical change.

Question 21

Enthalpy (H):

Answer 21

(H): the total amount of thermal energy in a substance.

Question 22

Enthalpy Change (ΔH):

Answer 22

the energy released to or absorbed from the surroundings
during a chemical or physical change.

Question 23

Molar enthalpy change (ΔHr):

Answer 23

the enthalpy change associated with a physical, chemical,
or nuclear change involving 1 mol of a substance; SI units J/mol.

Question 24

Molar Enthalpy Change of solution (ΔHsol):

Answer 24

the energy released or absorbed per mole
of solute being dissolved in solvent.

Question 25

Molar Enthalpy Change of Combustion (ΔHc):

Answer 25

the heat released when 1 mole of the substance undergoes complete combustion with oxygen at constant pressure.

Question 26

Molar Enthalpy change of vaporization (ΔHv):

Answer 26

the amount of energy needed to change one mole of a substance from the liquid phase to the gas phase at constant temperature and pressure.

Question 27

Molar Enthalpy Change of formation (ΔHf):

Answer 27

the enthalpy change of a chemical reaction in which one mole of a pure substance is formed from the free elements in their most stable states under standard state conditions.

Question 28

Molar Enthalpy Change of Neutralization (ΔHneut):

Answer 28

the energy released per mole of water formed during a neutralisation reaction.

Question 29

Potential Energy Diagram:

Answer 29

is the change in enthalpy for 1 mole of compound is formed from its elements, with all substances at their standard states.

Question 30

Bond Dissociation Energy:

Answer 30

is the change in enthalpy for 1 mole of compound is formed from its elements, with all substances at their standard states.

Question 31

Hessʼs Law:

Answer 31

is the change in enthalpy for 1 mole of compound is formed from its elements, with all substances at their standard states.

Question 32

Standard Enthalpy of Formation (ΔHfo):

Answer 32

is the change in enthalpy for 1 mole of compound is formed from its elements, with all substances at their standard states.

Question 33

Standard State:

Answer 33

is the change in enthalpy for 1 mole of compound is formed from its elements, with all substances at their standard states.

Question 33

Standard State:

Answer 33

is the change in enthalpy for 1 mole of compound is formed from its elements, with all substances at their standard states.