energy balance intro

Question 1

a system that does not exchange heat with the surroundings during the process

Answer 1

adiabatic system

Question 2

a system in which the pressure is constant during a process

Answer 2

isobaric system

Question 3

a system in which the volume is invariant during a process

Answer 3

isochoric system

Question 4

a system in which the temperature is invariant during a process

Answer 4

isothermal system

Question 5

any function whose value depends on how the process takes place and can differ for different histories

Answer 5

path function

Question 6

any function whose value depends on the state of the system and not upon its previous history

Answer 6

state function

Question 7

a system where both mass and energy can cross the boundaries

Answer 7

open system

Question 8

a system where no mass crosses the system boundaries, but energy can cross

Answer 8

closed system

Question 9

a system where neither mass nor energy crosses the boundaries; completely cut off from the surroundings

Answer 9

isolated system

Question 10

energy cannot be created or destroyed; it can only be transformed from one form to another or transferred between systems, but the total amount of energy remains constant

Answer 10

Law of Conservation of Energy

Question 11

energy is transferred in the form of either ________ or ______

Answer 11

heat or work

Question 12

the symbol of this is Q

Answer 12

heat

Question 13

unit of types of energy

Answer 13

J (SI) or Btu (imperial)

Question 14

the form of energy that is transferred between systems or a system and its surroundings due to a temperature difference

Answer 14

heat

Question 15

where do heat exists

Answer 15

during the transfer of energy

Question 16

heat naturally flows from a hotter object to a cooler one until ___________ is reached

Answer 16

thermal equilibrium

Question 17

system and surroundings have the same temperature

Answer 17

thermal equilibrium

Question 18

what type of function is heat

Answer 18

path function

Question 19

heat is positive when it is

Answer 19

going towards the system

Question 20

heat is negative when it is

Answer 20

going away from the system

Question 21

for the adiabatic system, Q =

Answer 21

0

Question 22

categories of heat transfer

Answer 22

conduction, convection, radiation

Question 23

the transfer of heat through a solid material without any movement of the material itself

Answer 23

conduction

Question 24

the transfer of heat through a fluid (liquid or gas) due to the bulk movement of the fluid itself

Answer 24

convection

Question 25

mechanism in conduction

Answer 25

vibration of particles

Question 26

the transfer of heat in the form of electromagnetic waves (primarily infrared radiation) without the need for a medium

Answer 26

radiation

Question 27

assuming that there are two bodies with different temperatures present inside the system boundary of an isolated system; if we let thermal equilibrium be reached, the heat transferred by the hotter object is equal to the heat absorbed by the cooler object

Answer 27

applying the law of conservation of energy in heat

Question 28

its symbol is W

Answer 28

work

Question 29

the energy transferred across the boundary of a system due to a force acting through a distance

Answer 29

work

Question 30

work done by the system on the surroundings (direction going towards the system boundary)

Answer 30

positive work

Question 31

work done on the system by the surroundings (direction going away from the system boundary

Answer 31

negative work

Question 32

type of function of work

Answer 32

path function

Question 33

kinds of work

Answer 33

mechanical, electrical, shaft, flow

Question 34

work due to the moving force

Answer 34

mechanical work

Question 35

work due to the moving electrical current through the electrical resistance in the circuit

Answer 35

electrical work

Question 36

work due to the rotational motion of the shaft against an external mechanical resistance

Answer 36

shaft work

Question 37

work due to the movement of fluid at the system

Answer 37

flow work

Question 38

symbol is KE

Answer 38

kinetic energy

Question 39

energy due to the motion of the body

Answer 39

kinetic energy

Question 40

represents the macroscopic motion of system or fluid as a whole

Answer 40

kinetic energy

Question 41

key points of kinetic energy

Answer 41

- a form of mechanical energy - a scalar quantity

Question 42

what is PE

Answer 42

potential energy

Question 43

a form of energy that the system possessed due to its position in a force field, typically a gravitational or electrical field

Answer 43

potential energy

Question 44

key points of potential energy

Answer 44

- position-dependent - scalar quantity

Question 45

its symbol is ∆U

Answer 45

internal energy

Question 46

total energy contained within a system due to the microscopic motions and interactions of its molecules, atoms, and subatomic particles

Answer 46

internal energy

Question 47

what does microscopic motions includes

Answer 47

- translational energy - rotational and vibrational energy - intermolecular forces - electronic energy

Question 48

key points of internal energy

Answer 48

- state function - extensive property - depends only on temperature, not in pressure or volume, in ideal gases - may also depend on pressure and phase for real subtances

Question 49

its symbol is ∆H

Answer 49

enthalpy

Question 50

the total heat content of a system is equal to the sum of its internal energy and the product of its pressure and volume (work)

Answer 50

enthalpy

Question 51

key points of enthalpy

Answer 51

- state function - extensive property - used in an open system

Question 52

its symbol is C

Answer 52

heat capacity

Question 53

unit of heat of capacity

Answer 53

J/K (SI) or Btu/°F (imperial)

Question 54

the amount of heat energy required to raise the temperature of a substance (or system) by one degree

Answer 54

heat capacity

Question 55

key points of heat capacity

Answer 55

- extensive property - varies with temperature, especially in gases and complex materials

Question 56

other types of heat capacity

Answer 56

Cv - heat capacity at constant volume Cp - heat capacity at constant pressure