Physics and Math Chapter 3: Thermodynamics

Question 1

What is the zeroth law of thermodynamics?

Answer 1

states that objects are in thermal equilibrium when they are at the same temperature

Question 2

What is temperature?

Answer 2

a qualitative measure of how hot or cold and object is; quantitatively, it is related to the average kinetic energy of the particles that make up a substance.

Question 3

What is thermal expansion?

Answer 3

Describes how a substance changes in length or volume as a function of the change in temperature.

Question 4

What is the thermodynamic system versus surroundings?

Answer 4

System = portion that we are interested in
Surroundings = everything that is not a part of the system

Question 5

Isolated systems

Answer 5

do not exchange matter or energy with the surroundings

Question 6

Closed systems

Answer 6

Exchange energy, but not matter with their surroundings

Question 7

Open systems

Answer 7

Exchange both energy and matter with their surroundings

Question 8

What are state functions?

Answer 8

pathway independent and are not defined by a process. Ex. pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy and entropy are all state functions.

Question 9

What are process functions?

Answer 9

describe pathway from one equilibrium state to another. Work and heat are process functions.

Question 10

What is the first law of thermodynamics?

Answer 10

statement of conservation of energy. The total energy in the universe can never decrease or increase

Question 11

What is the total internal energy in a closed system?

Answer 11

Heat flow into the system minus the work done by the system.

Question 12

What is heat?

Answer 12

The process of energy transfer between two objects at different temperatures that occurs until the two objects come into thermal equilibrium (reach the same temperature)

Question 13

What is specific heat?

Answer 13

The amount of energy necessary to raise one gram of a substance by one degree Celsius or one unit Kelvin

Question 14

What is the specific heat of water?

Answer 14

1 cal/g*K

Question 15

What is the heat of transformation?

Answer 15

During a phase change, heat energy causes changes in the particles’ potential energy and energy distribution, but not kinetic energy. Therefore, there is no change in temperature.

Question 16

Isothermal process.

Answer 16

temperature is constant, so change in internal energy is 0

Question 17

Adiabatic process

Answer 17

no heat is exchanged

Question 18

isobaric process

Answer 18

pressure is constant

Question 19

Isovolumetric process (isochoric)

Answer 19

volume is held constant and work by or on the system is 0

Question 20

What is the second law of thermodynamics?

Answer 20

in a closed system, energy will spontaneously and irreversibly go from being localized to being spread out.

Question 21

Entropy

Answer 21

a measure of how much energy has spread out or how spread out energy has become

Question 22

What are microstates?

Answer 22

As microstates increase, the potential energy of a molecule is distributed over that larger number of microstates, increasing entropy

Question 23

Are natural processes reversible?

Answer 23

Yes, every natural process is ultimately reversible.

Question 24

When is delta U positive/negative?

Answer 24

(+) Increasing temperature

(-) decreasing temperature

Question 25

When is heat (Q) positive/negative?

Answer 25

(+) heat flows into the system

(-) Heat flows out of the system

Question 26

When is work (W) positive/negative?

Answer 26

(+) work is done by the system (expansion)

-) work is done on the system (compression