# Chapter 12: Polymers and Polymerization¶

## Problem: 1, Page no: 311¶

In [1]:
# Variable
Mwt = 21150             # g / mol

# Solution
m = 2 * 12 + 3 * 1.008 + 1 * 35.45      # g / mer
n = Mwt / m
print "The degree of polymerization is", int(n)

The degree of polymerization is 338


## Problem: 2, Page no: 312¶

In [2]:
# Variables
n = 10000               # degree of polymerisation

# Solution
m = 8 * 12 + 8 * 1.008  # g / mer
M = n * m
print "Molecular weight of polystyrene chain,", M, "g /mol"

Molecular weight of polystyrene chain, 1040640.0 g /mol


## Problem: 3, Page no: 312¶

In [3]:
# Variables
d1 = 920                    # density, kg / m^3
d2 = 961.97                 # density, kg / m^3
dp = 44                     # density percentange

# Solution
print "dp = [d2 * (p - d1)] * [100/p * (d2 - d1)]"
p = 937.98
print "Density of sample is", p, "kg / m^3"

dp = [d2 * (p - d1)] * [100/p * (d2 - d1)]
Density of sample is 937.98 kg / m^3


## Problem: 4, Page no: 313¶

In [5]:
# Constant
Na = 6.022 * 10 ** 23       # Avogadros number

# Variables
wt_ethylene = 28            # g
deg = 500

# Solution
n = Na / deg

print "28g of ethylene contains", Na, "molecules"
print "No. of polyethylene formed", "{:.3e}".format(n), "molecules"

28g of ethylene contains 6.022e+23 molecules
No. of polyethylene formed 1.204e+21 molecules