Thermodynamics

Question 1

What is thermodynamic describe?

Answer 1

Processes that involve changes in temperature, transformation of energy, and the relationship between heat and work

Question 2

What does the system boundary separate?

Answer 2

The system from the surroundings

Question 3

What is the law of conservation of energy?

Answer 3

Energy can neither be created nor destroyed; it can only change form. The internal energy of the universe does not change. The energy lost by one must equal the energy gained by the other.

Question 4

What is internal energy (U)?

Answer 4

Energies associated with the structure and motion of molecules within the system

Question 5

What is internal energy as a state function?

Answer 5

(a state function) Change in internal energy depends only on the initial and final states and not on the path connecting these states. U system= U final-U inital

Question 6

What can the internal energy of a closed system be changed by?

Answer 6

Transfer of work (w) and heat (q) between the system and its surrounding

Question 7

What is the first law?

Answer 7

The change in internal energy of a closed system equals: U sys = q + w

Question 8

What must happen when heat is lost by the system?

Answer 8

It must be complemented by an input of work to make up for the loss of heat (and conversely)

Question 9

What is used to measure changes in energies at constant pressure?

Answer 9

The change in enthalpy

Question 10

What does enthalpy as a state function mean?

Answer 10

Change in internal energy depends only on the initial and final states and not on the path connecting these states.
H system=. H final- H inital

Question 11

What are the standard conditions for the standard enthalpy reactions?

Answer 11

289K

P= 1 bar

Question 12

What is the standard enthalpy of formation?

Answer 12

Enthalpy associated with the formation of 1 mole of a substance from its element in their most stable form

Question 13

What can the standard enthalpy of a reaction be determined from?

Answer 13

Standard enthalpy of formation

Question 14

What does it mean if enthalpy change is less than 0 (

Answer 14

Reaction is exothermic

Question 15

What does it mean if enthalpy change is more than 0 (>0)?

Answer 15

Reaction is endothermic

Question 16

What happens if reaction losses heat?

Answer 16

Transfer of thermal energy from the system to the surroundings

Question 17

What happens if the reaction gains heat?

Answer 17

Transfer of thermal energy from the surroundings to the system

Question 18

What does the first law of thermodynamics not predict?

Answer 18

Which of several possible processes will occur (i.e. which one is natural or spontaneous)

Question 19

What is the second law of thermodynamics state?

Answer 19

That the total entropy of a system and its surrounding always increases for a spontaneous process

Question 20

What is entropy?

Answer 20

It is related to energy dispersal, measures the microscopic disorder of a system. Units J.K-1

Question 21

What is the reaction if G

Answer 21

It is spontaneous

Question 22

What is the reaction if G=0?

Answer 22

The reaction is at equilibrium

Question 23

What is the reaction if G>0?

Answer 23

It is non spontaneous

Question 24

What does it mean if the K»1?

Answer 24

Mixture will mainly consist of the products at equilibrium

Question 25

What does heterogeneous systems do?

Answer 25

Omit terms for pure solids and liquids

Question 26

What is Kd?

Answer 26

The dissociation constant

Question 27

What is Kp?

Answer 27

The thermodynamic equilibrium constant