key terms pt.2

Question 1

work

Answer 1

force through a distance

Question 2

Mass density

Answer 2

Mass/Unit Volume

Question 3

Intensive Properties

Answer 3

properties which are independent of the size of the system (2 extensive = intensive) - SPECIFIC - NOT UNDERLINED

Question 4

Extensive Properties

Answer 4

properties which depend on the size/amount of/in the system (volume and energy) - UNDERLINED

Question 5

State Variables

Answer 5

intensive properties that specify/define the state of the system. (T,P)

Question 6

Gibb’s Phase Rule

Answer 6

F = C - P + 2
(F = DoF, C=#components, P=#phases)

Question 7

Steady State (Open System)

Answer 7

mass flow into and out of the system but there is no accumulation
- State variables in a steady state system are invariant with time

Question 8

Ideal Gas Law

Answer 8

PV_ = nRT

Question 9

Specific Notation

Answer 9

UNDERLINE = NOT SPECIFIC, NOT PER MASS

Question 10

Pressure

Answer 10

Force/Area (N/m^2)

Question 11

Isothermal

Answer 11

At constant temperature

Question 12

Critical Temperature

Answer 12

maximum temperature at which a fluid may exist as a liquid, temperature where vapor and pressure phases are identical - above this temperature = supercritical

Question 13

Saturation Conditions

Answer 13

where 2 phases coexist - can refer to either bubble or dew conditions

Question 14

Bubble Line

Answer 14

where boiling can occur

Question 15

Dew Line

Answer 15

where droplets can occur in vapor

Question 16

Critical Point

Answer 16

vapor and liquid phases are identical

Question 17

critical pressure

Answer 17

pressure where vapor and liquid phases are identical

Question 18

Superheated

Answer 18

vapor above its saturation temperature at a given pressure (above sat. temperature at system pressure)

USE SUPERHEATED TABLE when above saturation temp at a given pressure

Question 19

Linear Interpolation Formula

Answer 19

y = y1 + (( x - x1 )/( x2 - x1)) ( y2 - y1 )

Question 20

What must happen in order to use linear interpolation?

Answer 20

something must be constant!!

Question 21

What is true of U and H for ideal gases?

Answer 21

They are only a function of temperature!!

Question 22

Cv (heat capacity)

Answer 22

proportionality constant between temperature and INTERNAL ENERGY at a constant volume

Question 23

ideal gas heat capacity and specific heat relation

Answer 23

Cp = Cv + R

Question 24

isotherms

Answer 24

lines of constant temperature

Question 25

phase envelope

Answer 25

hump on fig 1.4, two phases coexist when system conditions are inside or on the envelope

Question 26

tie lines

Answer 26

horizontal lines inside the curves that show saturated liquid and saturated vapor volumes can coexist

Question 27

describe what happens to an isotherm in figure 1.4

Answer 27

1)from the right the isotherm starts in the vapor region and decreases in volume as it moves left.
2) The pressure rises as the vapor is isothermally compressed. 3) the volume reaches the saturation curve at the vapor pressure and the liquid phase begins.

Question 28

saturated steam

Answer 28

vapor at the dew point

Question 29

steam

Answer 29

vapor state of water

Question 30

Cp (heat capacity

Answer 30

proportionality constant between temperature and ENTHALPY at a constant pressure

Question 31

STATE VARIABLES

Answer 31

P, U, T, V