ppt 6

1. Gas Mixture
A. TOTAL MASS OF A MIXTURE
∑ im=m
B. MASS FRACTION
m
m
=x i
i
C. TOTAL MOLES OF A MIXTURE
∑in=n
D. MOLE FRACTION
n
n
=y i
i
E. EQUATION OF STATE (Mole Basis)
For the Mixture
TRn=PV
For the Components
iiii TRn=VP
F. EQUATION OF STATE (Mass Basis)
For the Mixture
mRT=PV
For the Components
iiiii TRm=VP

2. Where
i - refers to the components
m – mass kg
n – moles
x – mass fraction in decimal
y – mole fraction in decimal
P – absolute pressure in KPa
T – absolute temperature in Kelvin (K)
V – volume in m3
- universal gas constant. KJ/kgmol – K
R – gas constant, KJ/kg-K
G. AMAGAT’S LAW
The total volume of the mixture is equal
to the sum of the volume occupied by each
component at the mixture pressure P and
temperature T.
V1 V2 V3
P, T
TR
PV
=n
TR
PV
=n
TR
PV
=n
TR
PV
=n 3
3
2
2
1
1
321
321
321
321
VVVV
P
TR
TR
PV
TR
PV
TR
PV
TR
PV
TR
PV
TR
PV
TR
PV
TR
PV
nnnn


















 iVV
321
321
TTTT
PPPP


V
V
n
n
y ii
i 

3. H. DALTON’S LAW
The total pressure of a mixture P is equal
to the sum of the partial pressure that
each gas would exert at the mixture volume
V and temperature T.
P1 P2 P3 P
Components Mixture
321
321
VVVV
TTTT


TR
PV
=n
TR
VP
n
TR
VP
n
TR
VP
n 3
3
2
2
1
1 
321 nnnn 


















i
321
321
321
PP
PPPP
V
TR
TR
VP
TR
VP
TR
VP
TR
PV
TR
VP
TR
VP
TR
VP
TR
PV
P
P
n
n
y ii
i 

4. I. MOLECULAR WEIGHT OF A MIXTURE
R
3143.8
R
R
M
yM...MyMyMyM
MyM
332211
ii


 
M
3143.8
M
R
R
xR...RxRxRxR
RxR
332211
ii


 
J. GAS CONSTANT OF A MIXTURE
K. SPECIFIC HEAT OF A MIXTURE
1k
R
C;
1k
Rk
C
C
C
k
RCC
xC...CxCxCxC
CxC
xC...CxCxCxC
CxC
vp
v
p
vp
vv3v2v1v
viv
pp3p2p1p
piv
321
i
321
i












Where
M – molecular weight, kg/kgmole
R – Gas constant. KJ/kg-K
Cp – specific heat at P = C, KJ/kg-C,KJ/kg-K
Cv – specific heat at V = C, KJ/kg-C,KJ/kg-K
k – ratio of specific heat

5. L. GRAVIMETRIC AND VOLUMETRIC ANALYSIS
Gravimetric Analysis
Gives the mass fractions of the component
in the mixture.
Volumetric Analysis
Gives the volumetric or molal fractions of
the components in the mixture.
Conversions




i
i
i
i
i
ii
ii
ii
i
M
x
M
x
y
M
My
My
My
x