Cheme Thermo Exam 1

Front 1

The four rules to chemical engineering 101

Back 1

1. units are your best friend
2. IOGA
3. draw it to solve it
4. every measurement is incorrect

Front 2

is the physical/chemical changes in nature

Back 2

transformation

Front 3

1st Law for a closed system

Back 3

conservation of Energy

Front 4

corresponds to a snapshot of the intensive process variable values at a specific point in time

Back 4

state of a process

Front 5

considered "fundamental" coordinates as they are the only thermodynamic variables that can be expressed in absolute terms (there is a unique physical state associated with the zero value)

Back 5

pressure, volume, temperature, and entropy

Front 6

determines how many state variables must be specified for the phase to be fully fixed

Back 6

phase rule

Front 7

Q and w are _____ when the transfer of heat/work is from the surroundings to the system

Back 7

positive

Front 8

Are state variables path dependent? Explain

Back 8

no, differentials are exact

Front 9

Are W and Q variable path dependent? Explain

Back 9

yes, differentials are inexact

Front 10

numerical value that does not depend on the amount of material in the system or in any phase. Examples

Back 10

Intensive variables
T, P, physical properties/(per mol or per mass)

Front 11

numerical value changes with amount of material in the system or in any phase

Back 11

Extensive variables
m, n, total volume, total energy

Front 12

a state of no change, but also a state without any tendency to change

Back 12

Equilibrium

Front 13

when is a multi-phase mixture at equilibrium?

Back 13

P1=P2
T1=T2
m1=m2 (i.e. no driving force)

Front 14

Saturated ______ will start to condense if the system pressure is increased or any heat is removed from the system

Back 14

Vapor

Front 15

Saturated ______ will start partially vaporize if the pressure is reduced or any heat is added to the system

Back 15

Liquid

Front 16

5 characteristics of reversibility

Back 16

1.frictionless
2.never more than differentially removed from equil.
3.every point is at equilibrium
4. no driving force
5. can be retraced to initial conditions

Front 17

is reversible heat transfer possible?

Back 17

yes

Front 18

is reversible centrifugal pumps possible?

Back 18

no

Front 19

is reversible piston pumps possible?

Back 19

yes

Front 20

Which law implicitly defines internal energy (U)

Back 20

1st law

Front 21

are referred to as "specific heats" when the denominator units are mass rather than molar mass

Back 21

Cv and Cp

Front 22

forms of heat capacity that make the variables' physical property depend on their current state and independent of how they got there

Back 22

Cv and Cp

Front 23

What two cases allow for kinetic and potential energy to be neglected?

Back 23

entering and exiting fluid velocities are similar (i.e. densities and areas are similar)

the entrances and exits for the system are at the same elevation

Front 24

for what ideal state is the matter incompressible and has zero viscosity?

Back 24

liquid

Front 25

for what ideal state does the matter have no intermolecular forces between molecules of the gas?

Back 25

gas

Front 26

an ideal property where are all molecules interact in the same fashion regardless of the type of molecule

Back 26

solution

Front 27

the basic definition of 2nd law

Back 27

there is nothing random about the direction of changes that occur in nature

Front 28

"With the exception of water and wind, the partial conversion of heat into work is the basis of nearly all commercial production of _____"

Back 28

power

Front 29

can provide and receive unlimited amounts of heat with out changing the temperature of the reservoir

Back 29

Heat engines (energy sources and sinks)

Front 30

is the benchmark for heat engines as it operates in a completely reversible manner

Back 30

Carnot engine

Front 31

how we remove heat at a low temperature and reject at a higher temperature. The process involves linking two engines together

Back 31

refrigeration

Front 32

when is heat transfer between a system and reservoir reversible?

Back 32

when the temperature of the system and reservoir are the same

Front 33

what thermodynamic property is based on temperature and pressure only at its ideal gas state?

Back 33

entropy

Front 34

Is entropy conserved?

Back 34

no
Ssystem + Ssurrounding > 0

Front 35

What is included in ideal work?

Back 35

ideal shaft work and work obtainable by the carnot engines

Front 36

does steady state = equilibrium?

Back 36

No
steady state has driving force and resistance to change
equilibrium only accounts for driving force

Front 37

What are convince some properties?

Back 37

Gibbs, Enthalpy, Internal Energy

Front 38

Why is a nozzle reversible (ideal flow)

Back 38

-driving force is differential
-streamline flow therefore no turbulence or friction
-can retrace flow/restore flow

Front 39

all moving (unequilibrium) processes generate ______

Back 39

heat