THeRMO PRELIM

Question 1

An expression of the principle of conservation of energy which states that energy cannot be
created or destroyed but can only be transformed or changed from one form to another.

Answer 1

FIRST LAW OF THERMODYNAMICS

Question 2

_____ and ______ are means by which we can transfer or
transform energies from one form to another.

Answer 2

Work and Heat Flow

Question 3

True or False:
Work and Heat flow can exist without energy

Answer 3

False. There will be no work and heat flow without energy

Question 4

The energy possessed by a body by virtue of its POSITION

Answer 4

Potential Energy, PE. Note: POSITION

Question 5

The energy possessed by a body by virtue of its MOTION.

Answer 5

Kinetic Energy, KE. Note: MOTION

Question 6

The energy stored in a system in microscopic scale.

Answer 6

Internal Energy, U

Question 7

In a system (w/ molecules inside), how is KINETIC ENERGY present?

Answer 7

The MOTION of molecules causes KE.
- Thru vibration, translation, and rotation

Question 8

In a system (w/ molecules inside), how is POTENTIAL ENERGY present?

Answer 8

The BINDING ENERGY (Molecular attractive forcess) are associated with PE.

Question 9

Under PE, what holds the atoms together in a system?

Answer 9

BINDING ENERGY

Question 10

True or False:
In our naked eye, a steady glass of water means there is no motion in molecules.

Answer 10

FALSE
there is a mass of high-speed molecules moving at hundreds of meters per second @ microscopic scale

Question 11

The energy required to MOVE A MASS (thermodynamic substance) that enters a thermodynamic system from one point to another.

Answer 11

Flow work or Flow energy

Question 12

What causes a continous flow of mass in the Thermodynamic system

Answer 12

FLOW WORK or FLOW ENERGY

Question 13

In a flow work

The __________ enters the thermodynamic system and is pushed by the surroundings against the _________ and ____________ in the thermodynamic system, providing the system with ___________ in the process.

Answer 13

MASS;
RESISTANCE and LOCAL PRESSURE;
WORK;

Question 14

The sum of the internal energy and the work flow

Answer 14

Enthalpy, H

Question 15

Energies are transformed or transferred in two ways – by ________ or __________

Answer 15

Heat or Work

Question 16

the transfer of energy between two bodies because of its temperature difference.

Answer 16

Heat Energy or Thermal Energy, Q

Question 17

True or False
Energy CAN flow from low to high temperature

Answer 17

FALSE.
Energy ALWAYS flows from high to low energy, increasing Entropy.

Question 18

Heat flow will continue as long as there is ____________________ (2 words)

Answer 18

Temperature Difference

Question 19

a (positive or negative?) sign Q denotes that the heat is added on the system

or the direction of heat is going into the system

Answer 19

POSITIVE (+)

Question 20

(positive or negative) sign Q denotes that heat is rejected by the system or the direction

of heat is going out of the system.

Answer 20

NEGATIVE (-)

Question 21

a measure of the amount of energy that is UNAVAILABLE to do useful work in a closed system undergoing a change of state.

Answer 21

Entropy, S

Question 22

describes the microscopic disorder or degree of randomness of molecules in a closed thermodynamic system

Answer 22

ENTROPY, S

Question 23

Which Law of Thermodynamics

It states that the thermal energy in a closed system disperses over time until it reaches equilibrium.

Answer 23

2ND LAW OF THERMO.

Question 24

True or False:
As entropy increases, energy available to do useful work also increases

Answer 24

FALSE; Energy and Entropy are inversely proportional to each other

Question 25

When energy disperses, the pressure, temperature
and density __________ , therefore __________ (less or more?) energy is now available to do useful work.

Answer 25

Evens out;
Less

Question 26

True or False
Thermal Equilibrium increases Entropy

Answer 26

TRUE

Question 27

Energy is transferred through __________ when force, F, is applied to a body that causes it to move or displaced at a distance, d.

Answer 27

WORK

Question 28

the rate of doing work, expressed as amount of work per unit time or sometimes in horsepower.

Answer 28

POWER

Question 29

___________ states that the the mass going in the system is equal to the mass going out of the system

Answer 29

Conservation of Mass

Question 30

(positive or negative?) sign Work (W) denotes that the work is done by the system or the direction of work is going out the system

Answer 30

POSITIVE

Question 31

(positive or negative?) sign Work (W) denotes that work is done on the system or the direction of heat
is going into the system.

Answer 31

NEGATIVE

Question 32

Another term for thermodynamic system

Answer 32

Control volume

Question 33

defined as a region in space that is under consideration, it also contains mass or a thermodynamic substance.

It has specific boundaries that separate it from the external effects of the environment.

Answer 33

Thermodynamic System or Control Volume

Question 34

2 types of Thermodynamics systems

Answer 34

– Open Systems (Steady-flow systems)
– Closed systems (Non-flow Systems)

Question 35

A system able to exchange energy (heat and work) and mass across the system boundary

Answer 35

– Open Systems (Steady-flow systems)

Question 36

A System able to exchange energy (heat and work) across the system boundary but not mass.

Answer 36

– Closed systems (Non-flow Systems)