Thermochemistry

Question 1

What does the first law state?

Answer 1

Energy can’t be created or destroyed

Question 2

What is the equation of the internal energy of the system?

Answer 2

∆E = q+w

Question 3

The work of a system =

Answer 3

-(P∆V), where P = pressure

Question 4

What is ∆H?

Answer 4

Enthalpy

Question 5

What is ∆H when Pressure is constant?

Answer 5

Gravity

Question 6

What is it when a solid turns into a liquid?

Answer 6

Fusion / melting (+∆H)

Question 7

What is it when liquid turns into a gas?

Answer 7

Vaporization / Boiling (+∆H)

Question 8

What is it when a solid turns into a gas?

Answer 8

Sublimation (+∆H)

Question 9

What is it when a gas turns into a liquid?

Answer 9

Condensation (-∆H)

Question 10

What is it when a liquid turns into a solid?

Answer 10

Freezing (-∆H)

Question 11

What is it when a gas turns into a solid?

Answer 11

Deposition (-∆H)

Question 12

What are the types of systems found?

Answer 12

• Isolated
• Closed
• Open

Question 13

What is an isolated system?

Answer 13

One which can’t exchange energy or matter with the surroundings

Question 14

What is a closed system?

Answer 14

One that can exchange energy but not matter

Question 15

What is an open system?

Answer 15

One that can exchange both matter and energy with the surroundings

Question 16

∆H is

Answer 16

Enthalpy

Question 17

∆S is

Answer 17

Entropy

Question 18

∆G is

Answer 18

Standard Free Energy

Question 19

Internal energy is the sum of

Answer 19

KE, PE, and chemical energies

Question 20

Internal energy is

Answer 20

Constant

Question 21

How do you measure change in enthalpy?

Answer 21

∆H prod - ∆H react

Question 22

Isobaric processes are ones which occur at

Answer 22

Constant pressures

Question 23

The heat given or absorbed within isobaric processes results in

Answer 23

Changes in enthalpy

Question 24

Isochoric processes are ones which occur at

Answer 24

Constant volume

Question 25

The heat given or absorbed within isochoric processes results in

Answer 25

Changes in internal energy

Question 26

Isothermal processes are ones which occur at

Answer 26

Constant temperatures

Question 27

Adiabatic processes are ones which occur when

Answer 27

No heat is exchanged between the systems and surroundings

Question 28

In Adiabatic processes, the internal energy is equivalent to

Answer 28

Work

Question 29

Hess's Law states that

Answer 29

Enthalpies are additive

Question 30

Entropy is the measure of

Answer 30

Disorder in a system

Question 31

Which phase has the most disorder?

Answer 31

Gas

Question 32

Which phase has the least disorder?

Answer 32

Solid

Question 33

Maximum entropy is accomplished at

Answer 33

Equilibrium

Question 34

∆Suniverse equals to

Answer 34

∆S system + ∆S surroundings, equalling to 0

Question 35

Entropy is a

Answer 35

State function

Question 36

What are the three laws of Thermodynamics?

Answer 36

- Conservation of Energy - All spontaneous processes are ∆S system + ∆S surroundings > 0 - Entropy of perfectly crystalline substance at 0K is 0

Question 37

Gibbs Free Energy communicates how

Answer 37

Changes in enthalpy and entropy affect reactions

Question 38

What is the equation for Gibbs Free Energy?

Answer 38

∆G = ∆H - T∆S

Question 39

What happens if ∆G is negative?

Answer 39

Reaction is spontaneous and moves forward

Question 40

What happens if ∆G is positive?

Answer 40

Reaction is not spontaneous and moves in reverse

Question 41

What happens if ∆G is 0?

Answer 41

System is in equilibrium

Question 42

What does spontaneity indicate?

Answer 42

It reaction will occur

Question 43

What happens when -∆H and -∆S?

Answer 43

Spontaneous at low temperatures

Question 44

What happens when -∆H and +∆S?

Answer 44

Spontaneous at all temperatures

Question 45

What happens when +∆H and +∆S?

Answer 45

Spontaneous at high temperatures

Question 46

What happens when +∆H and -∆S?

Answer 46

Nonspontaneous at all temperatures

Question 47

What is a process in which no heat is exchanged?

Answer 47

Isothermal