Answer Happy

d) Explain how you would produce one of these polymers in
the isotactic form.
e) Explain why the molar mass of the polymer produced by
step-growth polymerization varies greatly with reaction time but
the molar mass of the polymer from free-radical polymerization is
almost independent of time.
f) If the average molar mass is 55000 g mol–1 for the
polymer produced when a chain- growth polymerization has proceeded
10% towards completion, what is the average molar mass for the rest
of the reaction mixture? You may ignore any solvent or initiator
present.
g) Explain the difference between a polymerization
inhibitor and a retarder. What are some practical uses of these
additives?
h) Polyvinyl chloride is used to manufacture both plumbing
pipes and also garden hoses. These materials have very different
glass transition temperatures. Explain how this is achieved.
2:12 2 of 12 xn Page 1 of 12 Useful formulae and data R= 8.314 J K¹ mol-¹ NA 6.022 × 1023 mol-¹ 0.00 °C corresponds to 273.15 K 1 J = 1 Nm 1 = (1 - p) (1 + p) (1 - p) NA r = NB = kp (fkall) ³ In2 ka v= V = xn (1+r) (1 + r - 2rp) xw 1 t1/2 V 2kaf [1] 1 1 [S] + Cs xn Хо [M] (rifi²+f₁f₂) (rifi²+2f₁f2 +r₂f2²) = F₁ y = -IRTInc + constant Y = mc X or r= [M] NA (NB +2NC) A = 1 TNA gh(pi-pv)r 2 cos 0 1 C + k1xm xm 1 1 1 = (KVM) p + √m pV = nRT for a perfect gas A = Nm NÃO Relative atomic masses: H = 1.01, C = 12.00, O = 16.00, N = 14.01, C1 = 35.45 Donn 2 of 12 ←
C 3.00×108 m.s-1 1.38x10-23 J.K-¹ 6.63×10-34 J.s ħ 1.05×10-34 J.S. -19 1 eV 1.60x10 J -27 1 u 1.67×10 kg Photon energy E = hf c = fa 2=² Molecular vibration 1 k mm₂ = μl = 2πνμ m₂ + m₂ where k is spring constant or force constant and μ is reduced mass E=hf = 2KT 3 kT where k is Boltzmann constant Molecular rotation I = μr² E₁=J(J+1) Erot = KT k h Spectroscopy Speed of light in vacuum Boltzman's constant Plank constant h/2π = hc 2 ħ² ::