# Chapter 1 - The properties of gases¶

## Example E1 - Pg 17¶

In [2]:
#Calculate the pressure in the glass flask
#Initialzation of variables
m=1.25 #g
MN2=28.02 #g/mol
T=20+273.15 #K
V=0.25#L
#Calculations
P=m*8.31451*T/(MN2*V)
#Results
print '%s %.1f %s' %('Pressure in the gas flask = ',P,'kPa')

Pressure in the gas flask =  434.9 kPa


## Example I2 - Pg 19¶

In [2]:
#calculate the partial pressures of Oxygen, Nitrogen and Argon
#Initialzation of variables
xN2=0.780
xO2=0.210
xAr=0.009
P=100 #kPa
#Calculations
PN2=xN2*P
PO2=xO2*P
PAr=xAr*P
#Results
print '%s %.1f' %('Partial pressure of Nitrogen(kPa) = ',PN2)
print '%s %.1f' %('\n Partial pressure of Oxygen(kPa) = ',PO2)
print '%s %.1f' %('\n Partial pressure of Argon(kPa) = ',PAr)

Partial pressure of Nitrogen(kPa) =  78.0

Partial pressure of Oxygen(kPa) =  21.0

Partial pressure of Argon(kPa) =  0.9


## Example I3 - Pg 22¶

In [5]:
#Calculate the percentage loss of speed of air molecules
#Initialzation of variables
import math
T1=298. #K
T2=273. #K
#Calculations
factor=math.sqrt(T2/T1)
percentage=(1-factor)*100
#Results
print '%s %.3f' %('Factor by which speed is reduced = ',factor)
print '%s %d' %('Percentage loss of speed of air molecules = ',percentage)

Factor by which speed is reduced =  0.957
Percentage loss of speed of air molecules =  4


## Example I4 - Pg 24¶

In [4]:
#Calculate the ratio of rates of effusion
#Initialzation of variables
import math
MH2=2.016 #g/mol
MCO2=44.01 #g/mol
#calculations
ratio=math.sqrt(MCO2/MH2)
#results
print '%s %.3f' %('ratio of rates of effusion = ',ratio)

ratio of rates of effusion =  4.672


## Example I5 - Pg 25¶

In [7]:
#Calculate the mean free path and collision frequency
#Initialzation of variables
import math
T=25+273. #K
sigma=0.4*math.pow(10,(-18)) #m^2
P=math.pow(10,5) #Pa
c=481.8 #m/sec
#Calculations
Lambda=8.31451*T/(math.pow(2,0.5) *6.022*math.pow(10,23) *sigma*P)
frequency=math.pow(2,0.5) *6.022*math.pow(10,23) *sigma*P*c/(8.31451*T)
#Results
print '%s %.1e %s' %('Mean free path =',Lambda,'m')
print '%s %.1e %s' %('\n Collision frequency =',frequency,'m')

Mean free path = 7.3e-08 m

Collision frequency = 6.6e+09 m