1 Fundamental Concepts of Thermodynamics

Question 1

What is thermodynamics?

Answer 1

A science that describes the behaviour of matter and transformation between different forms of energy on a macroscopic scale.

Question 2

What are bulk properties?

Answer 2

Variables used to describe a thermodynamic system. Generally directly obtainable via measurements.

Question 3

Give examples of bulk properties.

Answer 3

Pressure, Density, Volume, Temperature.

Question 4

What is statistical thermodynamics?

Answer 4

Study of atomic and molecular properties for calculating macroscopic properties of matter.

Question 5

What is a thermodynamic system?

Answer 5

A physical system studied using the principles of thermodynamics.

Question 6

What constitutes a ‘surrounding’?

Answer 6

The universe which lies outside the boundaries of the system under study.

Question 7

What is a open system?

Answer 7

A system which can exchange matter and energy with its surroundings.

Question 8

What is a closed system?

Answer 8

A system which can exchange energy with its surroundings, but not matter.

Question 9

What is an isolated system?

Answer 9

A system that can exchange neither matter or energy with its surroundings.

Question 10

What is a boundary?

Answer 10

The interface between a system and its surroundings. It determinesif energy or mass can be transfered through it and thus determines the type of system (open, closed, or isolated).

Question 11

What is pressure?

Answer 11

Force per unit area.

Question 12

Define equilibrium.

Answer 12

Equilibrium is a state with respect to a variable where that variable does not change with time and has the same value throughout the whole system and suroundings.

Question 13

Define thermodynamic equilibrium.

Answer 13

A condition where equilibrium exists with respect to Pressure, Temperature, and Concentration.

Question 14

Define adiabatic process.

Answer 14

Condition where there are no heat exchange between system and surroundings.

Question 15

What is the zoroth law of thermodynamics?

Answer 15

Two systems that are seperately in thermal equilibrium with a third system are also in thermal equilibrium with one another.

Question 16

What is any thermal measuring system based on?

Answer 16

The value measured (temperature) is a single valued continuous and monotonic function of some thermometric system property. e.g. volume of a liquid, the electrical resistance of a metal or semiconductor, or the electromotive force generated at the junction of 2 dissimiliar metals.

Question 17

What is the formula to convert temperature from Kelvin to Celcius?

Answer 17

T(K) = 273.15 + T(∘C)

Question 18

What is an equation of state?

Answer 18

An equation which relates the state variables which describe the system of interest.

Question 19

What is the ideal gas equation of state?

Answer 19

PV = nRT = ρRT = NkT. where k is boltzman constant, N is the number of molecules.

Question 20

What is an intensive variable?

Answer 20

Variables that are independent of the size of the system. e.g. P, T.

Question 21

What is an extensive variable?

Answer 21

Variables which are proportional to the size of the system. e.g. V, n.

Question 22

How do you apply the ideal gas law to a ideal gas mixture?

Answer 22

P = ∑nᵢRT/V = ∑Pᵢ = P₁+P₂+P₃+…

Question 23

Convert 1atm to Pa

Answer 23

1 atm = 101,325 Pa exactly.

Question 24

Convert 1 bar into Pa

Answer 24

1 bar = 10⁵ Pa

Question 25

Convert 1 atm to Torr

Answer 25

1 atm = 760 Torr

Question 26

Convert 1 psi to Pa

Answer 26

1 psi = 6894.8 Pa

Question 27

State the value of the gas constant.

Answer 27

R = 8.314 JK⁻¹mol⁻¹, R = 8.314 Pa m³K⁻¹mol⁻¹, R = 8.206 *10⁻² L atm K⁻¹ mol⁻¹

Question 28

State the 2 assumptions that describe an ideal gas.

Answer 28

Atoms and molecules of an ideal gas do not interact with each other and are treated as point masses.

Question 29

Provide the van der Waals equation of state.

Answer 29

P = (nRT)/(V-nb) - (n²a)/V²