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黎曼格

新虫 (初入文坛)

[求助] 两道高化题目。

1.Styrene is polymerized by free-radical mechanism in solution. The initial monomer
and initiator concentrations are 1 M (molar) and 0.001 M, respectively. At the
polymerization temperature of 60℃, the initiator efficiency is 0.30. The rate constants
at the polymerization temperature are as follows:
kd = 1.2×10-5 s-1
kp = 176 M-1s-1
kt = 7.2×107 M-1s-1
Given this information , determine the following:
(a) Rate of initiation at 1 min and at 16.6h
(b) Steady-state free-radical concentration at 1 min
(c) Rate of polymerization at 1 min
(d) Average fee-radical lifetime, τ at 1 min, where τ is defined as the radical
     concentration divided by the rate of termination.
(e) Number-average degree of polymerization at 1 min


2.A polymer is fractioned and is found to have the molecular-weight distribution shown below. For this continuous distribution, calculate the following:(a) the number-average;(b)the weight-average;and (c)the z-average molecular weight of the distribution.(分子量是从10^3到10^5)

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