CH0 - Introduction to Thermodynamics

Question 1

Zeroth Law

Answer 1

If systems A and B are in equilibrium with system C, they must be in thermal equilibrium with each other

Question 2

First Law

Answer 2

ΔU = Q - W

Question 3

Second Law

Answer 3

Entropy tends to a maximum, hence entropy is always increasing.
dS = 0 for a reversible reaction
ds > 0 for an irreversible reaction

Question 4

Third Law

Answer 4

At 0K temperature, entropy S = 0

Question 5

How to find work (J)?

Answer 5

Work (J) = Force (N) x Distance (m) - Force & displacement

Work (J) = Force (N/m^3) x Volume (m^3) - Compression

Question 6

Newton’s 3rd Law

Answer 6

For every action, there is an equal and opposite reaction

Question 7

How to find potential energy?

Answer 7

Potential energy (J) = Mass(kg) x Gravity (9.81 m/s^2) x Height (m)

Question 8

Types of potential energy?

Answer 8

1. Gravitational (due to an object’s mass & position in a gravitational field)
2. Magnetic (due to a magnetic object’s position in a magnetic field)
3. Electrical (due to size of an electrical charge and its position in an electrical field)
4. Elastic (amount of energy stored in an elastic material to restore to its original shape and position)

Question 9

What is kinetic energy?

Answer 9

Form of energy that an object or a particle has by reason of motion

Question 10

Types of kinetic energy?

Answer 10

1. Translational (from an object’s motion in a straight line from one place to another)
2. Rotational (from an object’s vibrational motion)
3. Vibrational (from an object’s vibrational motion)

Question 11

How to find kinetic energy?

Answer 11

KE (J) = 1/2 m(kg) x v(velocity)^2

Question 12

Other types of work

Answer 12

1. Electrical (Volts(V) x Current (I) x Time (t))
2. Magnetic (Magnetic field strength (H) x Magnetization (M))
3. Heat of fusion (Carbon Heat of fusion = 105kJ/mol)

Question 13

What is internal energy, U?

Answer 13

Sum of all microscopic forms of energy of a system and may be viewed as the sum of all kinetic and potential energy, inclusive of energies of all chemical bonds and free conduction electrons in metals.

Question 14

What is internal energy dependent on?

Answer 14

Inherent qualities and properties of the materials of the system. (e.g composition, physical forms and environmental variables like pressure, temperature, etc)

Question 15

What are the forms of internal energy?

Answer 15

Mechanical, Chemical, Electrical, Magnetic, Surface, Thermal and more.

Question 16

What is the relationship between internal energy and temperature?

Answer 16

Internal energy will increase when the temperature increases.

Question 17

ΔU

Answer 17

Change in internal energy

Question 18

Q

Answer 18

Heat absorbed by a system

Question 19

Variable with an underscore

Answer 19

per unit mass or per unit mol

Question 20

H

Answer 20

Enthalpy

Question 21

S

Answer 21

Entrophy

Question 22

Cp/Cv

Answer 22

Constant pressure heat capacity/ Constant volume heat capacity

Question 23

Ω

Answer 23

Number of accessible microstates

Question 24

lw

Answer 24

Lost work

Question 25

F

Answer 25

Helmholtz Free Energy

Question 26

μ

Answer 26

Chemical potential = molar Gibbs Free Energy

Question 27

What is power rule?

Answer 27

d/dx (kx)^n = nkx^(n-1)

Question 28

When is partial differentiation used?

Answer 28

When there is a multivariate function; y = f(x) + f(z), start by differentiating y with respect to x and keep z constant then differentiate y with respect to z

Question 29

What is the partial differential of the Ideal Gas Law

Answer 29

PdV + VdP = nRdT