Chapter 2 - Structures of Condensed Phases

Example 1 - pg 74

In [1]:
#calculate the size of cubic unit cell
#initialisation of variables
import math
l= 1.5418 #A
a= 19.076 #degrees
d2= 1.444 #A
#CALCULATIONS
d= l/(2*math.sin(a*math.pi/180.))
a= math.sqrt(8*d2*d2)
#RESULTS
print '%s %.4f %s' % (' size of cubic unit cell =',a,'A')

 size of cubic unit cell = 4.0842 A

Example 2 - pg 75

In [2]:
#calculate the Density of silver
#initialisation of variables
M= 107.88 #gm
z= 4
v= 4.086 #A
N= 6.023*10**23
#CALCULATIONS
d= z*M/(v**3*10**-24*N)
#RESULTS
print '%s %.4f %s' % (' Density of silver =',d,'gm cm^-3')

 Density of silver = 10.5025 gm cm^-3

Example 3 - pg 75

In [3]:
#calculate the molecular weight
#initialisation of variables
d= 1.287 #g cm**-3
a= 123 #A
z= 4
#CALCULATIONS
M= d*6.023*10**23*a**3*10**-24/z
#RESULTS
print '%s %.1e %s' % (' molecular weight =',M,'gm ')

 molecular weight = 3.6e+05 gm

Example 4 - pg 78

In [4]:
#calculate the radius of silver atom
import math
#initialisation of variables
a= 4.086 #A
#CALCULATIONS
d= a*math.sqrt(2)
r= d/4.
#RESULTS
print '%s %.3f %s' % (' radius of silver atom=',r,' A ')

 radius of silver atom= 1.445  A

Example 5 - pg 99

In [5]:
#calculate the surface tension
import math
#initialisation of variables
M= 38.3 #mg cm^-1
d= 13.55 #g cm^-3
p= 0.9982 #g cm^-3
g= 980.7 #cm/sec^2
l= 4.96  #cm
#CALCULATIONS
r= math.sqrt(M*10**-3/(d*math.pi))
R= r*p*g*l/2
#RESULTS
print '%s %.1f %s' % (' surface tension =',R,' ergs cm^-2 ')

 surface tension = 72.8  ergs cm^-2

Example 6 - pg 103

In [6]:
#calculate the dipole moment of water
#initialisation of variables
import math
r= 1.333
d= 0.9982 #g cm**-3
m= 18.02 #gm
Pm= 74.22 #cc
k= 8.314*10**7 
N= 6.023*10**23
T= 293 #k
#CALCULATIONS
Rm= ((r**2-1)/(r**2+2))*m/d
u= math.sqrt(9*k*T*(Pm-Rm)/(4*math.pi*N**2))
#RESULTS
print '%s %.2e %s' % (' dipole moment of water =',u,'e.s.u ')

 dipole moment of water = 1.84e-18 e.s.u

Example 7 - pg 103

In [7]:
#calculate the radius of argon atom
#initialisation of variables
a= 1.66*10**-24 #cm**3
#CALCULATIONS
r= a**(1/3.)/10**-8
#RESULTS
print '%s %.2f %s' % (' radius =',r,'A ')

 radius = 1.18 A

Example 8 - pg 104

In [8]:
#calculate the index of refraction
import math
#initialisation of variables
N= 6.023*10**23 #molecules
a= 10**-24
k= 0.89
cl= 3.60
M= 74.56 #gms
d= 1.989 #g/cm^3
#CACLULATIONS
Rm= 4*math.pi*N*(k+cl)*a/3
r= Rm*d/M
n= math.sqrt((2*r+1)/(1-r))
#RESULTS
print '%s %.3f' % (' index of refraction= ',n)

 index of refraction=  1.516

Example 9 - pg 104

In [9]:
#calculate the radius of K and Cl atoms
#initialisation of variables
v= 3.6 #cc
v1= 0.89 #cc
s= 3.146 #A
#CALCULATIONS
r= (v/v1)**(1/3.)
r1 = s/(1+r)
r2 = s-r1
#RESULTS
print '%s %.3f %s' % (' radius of k+=',r1,'A ')
print '%s %.3f %s' % (' \n radius of cl-=',r2,'A ')

 radius of k+= 1.213 A 
 
 radius of cl-= 1.933 A

Example 10 - pg 107

In [10]:
#calculate the angle of rotation
#initialisation of variables
g= 10 #gm
d= 1.038 #gm/mol
M= 100 #gm
x= 66.412
y= 0.127
z= 0.038
l= 20 #cm
#CALCULATIONS
p= g/(M/d)
X= x+y-z
ar= X*l*p/10.
#RESULTS
print '%s %.2f %s' % (' angle of rotation=',ar,'degrees ')

 angle of rotation= 13.81 degrees

Example 11 - pg 108

In [11]:
#calculate the viscosity of toluene
#initialisation of variables
t= 68.9 #sec
t1= 102.2 #sec
p1= 0.866 #g/cm^3
p2= 0.998 #gm/cm^3
n= 0.01009 #dynesc/cm^2
#CALCULATIONS
N= n*t*p1/(t1*p2)
#RESULTS
print '%s %.5f %s' % (' viscosity of toluene=',N,'dyne sec/cm^2 ')

 viscosity of toluene= 0.00590 dyne sec/cm^2