Thermochemistry

Question 1

System

Answer 1

The particular part of the universe being studied

Question 2

Isolated system

Answer 2

Cannot exchange energy or matter with the surroundings

Question 3

Closed system

Answer 3

Can exchange energy but not matter with the surroundings

Question 4

Open system

Answer 4

Can exchange energy and matter with the surroundings

Question 5

Isothermal process

Answer 5

Systems at constant temperature

Question 6

Adiabatic process

Answer 6

Systems with no heat exchange

Question 7

Isobaric process

Answer 7

Systems at constant pressure

Question 8

Isochoric process

Answer 8

Systems at constant volume

Question 9

Heat (q)

Answer 9

A form of energy easily transferred to or from a system due to a temperature differences
absorbed = +
lost = -
q = mcT

Question 10

Specific heat

Answer 10

How much energy it takes to raise the temperature of a material

Question 11

State function

Answer 11

Properties whose magnitude does not depend on the path of change
P, V, T, H, S, G, U

Question 12

Standard conditions

Answer 12

298 K
1 atm
1 M concentration

Question 13

Standard state

Answer 13

A substance in its most stable form under standard conditions

Question 14

Enthalpy (H)

Answer 14

A process equal to the heat absorbed or given off by the system at constant pressure
Endothermic = +
Exothermic = -

Question 15

Standard heat of formation

Answer 15

The enthalpy change if one mole of a compound is formed directly from its elements in their standard states

Question 16

Standard heat of reaction

Answer 16

The enthalpy change when a reaction is carried out under standard conditions

Question 17

Hess’s Law

Answer 17

Enthalpies of reactions are additive

Question 18

Bond dissociation energy

Answer 18

The energy required to break a specific chemical bond in one mole of gaseous molecules

Question 19

Heat of combustion

Answer 19

The heat released for the complete combustion of a compound in its standard state to form stable products in their standard states

Question 20

Entropy (S)

Answer 20

A measure of disorder of a system

Energy/temp = J/K or cal/K

Question 21

Second law of thermodynamics

Answer 21

All spontaneous processes proceed such that the entropy of the system plus its surroundings increases

Question 22

Gibbs free energy

Answer 22

The max amount of energy released by a process occurring at constant temperature and pressure
- = spontaneous
+ = nonspontaneous
0 = equilibrium

Question 23

Standard free energy

Answer 23

The delta G of a process occurring with reactants in their standard states at standard conditions

Question 24

Standard free energy of formation

Answer 24

The free energy change when 1 mol of a compound in its standard state is formed from its elements in their standard states under standard conditions