Answer:
a) 88.9% b) 2211
Explanation:
a)k = (443 – 49 s)/49 s = 8.04
K = Cs/Cm = k(Vm/Vs)
Vm = V cylinder = π(d²/4)L = π[(0.187 mm)²/4)L = 0.0275 mm²L
Vs = Vtube = Vouter cylinder – Vinner cylinder = π[(0.187 mm)²/4]L – π{[(0.187 mm – 2(0.00054 mm)]²/4}L
<em>For a thin tube, Vtube = πtdL, where t = film thickness.</em>
<em />
This same equation also can be derived from the first equation
(Vs = Vtube = Vouter cylinder – Vinner cylinder )
since Vtube = π[(0.187 mm)2/4]L – π[(0.187 mm)2/4]L + π(0.187 mm)(0.00054 mm)L – π(0.0054 mm)²L.
The first two terms cancel out and since 0.187 mm >> 0.00054 mm the last term is negligible.
Vs = Vtube = π(0.187 mm)(0.00054 mm)L = 0.0001 mm²L
K = k(Vm/Vs) = 8.04 x (0.0275 mm²L/0.0001 mm²L) = 2211
<em>the L cancels out so the </em>(0.0275<em>column length is actually not needed</em>
b) fraction of time spent in stationary phase = time spent in stationary phase/total time spent
fraction of time spent in stationary phase = (443 – 49 s)/443 s = 0.889 = 88.9%
