Chapter 2: Thermodynamics principles

Question 1

Chapter 2A:

Define the kinetic theory of matter

Answer 1

The kinetic theory of matter states that all matter is made up of smaller particles in constant motion.

Question 2

Chapter 2A:

Outline the particle arrangement, particle motion, and physical properties of a solid.

Answer 2

Particle arrangement: The particles within a solid are packed tightly together in a regular arrangement.

Particle motion: There is no overall movement (motion) of the particles within a solid. These particles instead vibrate at a single location.

Physical properties: Solids contain a definite shape and volume.

Question 3

Chapter 2A:

Outline the particle arrangement, particle motion, and physical properties of a liquid.

Answer 3

Particle arrangement: The particles within a liquid have a random arrangement.

Particle motion: The particles within a liquid are free to move around each other, causing random collisions.

Physical properties: Liquids have an indefinite shape with a definite volume.

Question 4

Chapter 2A:

Outline the particle arrangement, particle motion, and physical properties of a gas.

Answer 4

Particle arrangement: All gases possess a random arrangement of particles that are spread far from each other.

Particle motion: The particles within a gas are free to move around each other at really high speeds, causing random collisions.

Physical properties: Gases have both an indefinite shape and volume.

Question 5

Chapter 2A:

Define the “internal energy,” of a system/object.

Answer 5

The internal energy of a system refers to all the energy associated with the motion of particles (kinetic energy) in a system and through the interactions of the particles within that system (potential energy).

Question 6

Chapter 2A:

Define “kinetic energy.”

List the three kinds.

Answer 6

Kinetic energy refers to the energy associated with the motion of particles within a certain object or system.

Transnational energy:
Vibrational energy:
Rotational energy:

Question 7

Chapter 2A:

Define “temperature.”

Answer 7

Temperature is defined as the average transnational energy of particles within a certain system/object.

Note: The particles within a system can have ranging speeds. Hence, the “average,” translational energy of a system dictates its temperature.

Question 8

Chapter 2A:

Define “potential energy.”

Answer 8

Potential energy is defined as the energy associated with any object due to its position and the presence of another object.

Question 9

Chapter 2A:

Define “thermal energy.”

Answer 9

Thermal energy is defined as the energy associated with the movement of microscopic particles within a system.

Question 10

Chapter 2A:

Define a “thermal equilibrium.”

Answer 10

A thermal equilibrium occurs when two or more systems have the same temperatures. Hence, there is no net transfer of heat when these two systems come into thermal contact.

Question 11

Chapter 2B:

Define the term “heat.”

Answer 11

Heat is defined as a form of energy (thermal energy specifically) that flows between or within systems due to ranging temperatures.

Heat is expressed in joules.

Question 12

Chapter 2B:

List the different methods of heat transfer

Answer 12

Thermal Conduction
Convection
Thermal radiation

Question 13

Chapter 2B:

Define “thermal conduction.”

Answer 13

Conduction is a method of heat transfer (occurring primarily in solids due to their particles arrangements) where two systems come into physical contact, with heat being transferred from the hotter system to the colder system.

When these two systems come into physical contact, particles will collide and transnational energy will be transferred from the hotter substance to the colder substance until a thermal equilibrium is achieved.

Question 14

Chapter 2B:

Define a fluid

Answer 14

A fluid describes a substance that is either in a gas or liquid state of matter.

Question 15

Chapter 2B:

Define “convection.”

Answer 15

A form of heat transfer that occurs within a fluid, where there is an overall movement of matter. This heat transfer occurs as the fluid has ranging levels of temperatures within different regions of that fluid.

Convection can occur when the lower region of a fluid contains a greater temperature and is hence displaced by the upper region of that fluid which has a lower temperature (with this lower rate of transnational energy making this region of the fluid more dense). This means gravity will drag down that region of the fluid.

Convection will only occur if a fluid is provided with a source of heat.

Question 16

Chapter 2B:

Define a “convection cell.”

Answer 16

A convection cell is defined as a cyclical flow matter within a fluid due to ongoing convection.

Question 17

Chapter 2B:

Distinguish between natural and forced convection.

Answer 17

Natural convection occurs where the heat transfer itself is causing the convection flows. (Movement of matter)

In contrast, forced convection occurs when the convection flows are caused by an external force.

Question 18

Chapter 2B:

Define “Thermal radiation.”

Answer 18

Thermal radiation is a form of heat transfer occurring due to the emission of electromagnetic radiation from an object.

With the prominent form of light emitted being infrared.

Question 19

Chapter 2B:

Describe how an object emits thermal radiation

Answer 19

Due to the random motion of particles in a system, these particles will often collide, with their kinetic energy (mainly transnational energy) being transformed into electromagnetic radiation and emitted by that object.

Which decreases the internal energy of that system which has emitted thermal radiation.

Question 20

Chapter 2c:

Define the term “boil.”

Answer 20

Boiling is defined as the conversion of a liquid into a gas via a transfer of latent heat.

Question 21

Chapter 2c:

Define the term “condense.”

Answer 21

To condense a substance is to convert its state from a gas to a liquid via a transfer of latent heat.

Question 22

Chapter 2c:

Define the term “freeze.”

Answer 22

To freeze a substance is to convert its state of matter from a liquid to a solid via a transfer of latent heat.

Question 23

Chapter 2c:

Define the term “melt.”

Answer 23

To melt a substance is to convert its state of matter from a solid to a liquid via a transfer of latent heat.

Question 24

Chapter 2c:

Define “specific heat capacity.”

Answer 24

Specific heat capacity is the heat (Thermal energy-transnational energy) required to increase the temperature of a certain mass of a substance by 1 Kelvin, or by 1 degree Celsius.

Question 25

Chapter 2c:

Define “latent heat.”

Answer 25

Latent heat is the energy absorbed or released by a substance responsible for a state change. It’s hidden as potential energy transfer, which breaks or creates bonds between particles-absorb or releases potential energy within a substance.

Question 26

Chapter 2c:

Define “latent heat of fusion.”

Answer 26

The latent heat of fusion is the heat per unit of mass required to change the state of a substance from a solid to a liquid.

Question 27

Chapter 2c:

Define “latent heat of vaporization.”

Answer 27

The latent heat of vaporization is the heat per unit of mass required to change the state of a substance from a liquid to a gas.

Question 28

Chapter 2c:

Define “evaporation.”

Answer 28

Evaporation is the process of the particles at the surface of a liquid, which are found in a gaseous state (meaning they have greater levels of kinetic and potential energy) escaping from that liquid’s surface and into its surroundings, decreasing the temperature (average rate of transnational energy) of that liquid.

Question 29

Chapter 2c:

List some of the factors affecting evaporation.

Answer 29

: Surface area of the liquid. A greater surface area will increase the evaporating rate of a liquid.

: The presence of wind. Wind can carry particles away from the liquid which increases the rate of evaporation.

: Temperature. A greater temperature will increase the rate of evaporation.

: Humidity. The less humidity in the surroundings of the liquid, the greater the rate of evaporating will be.