Two perfectly mixed vessels of 10 liters each and both at 1 atm and 120 C are

respectively filled with n-butanol C4H9OH and air. At time t = 0, the two vessels are via

a pipe connected to each other at 120 C and 1 atm. This pipe has a length of 10 cm and

a diameter of 1 cm. No reaction occurs during the mixing of the gases. All performing

gas phases are assumed to be ideal. For the calculation of the molecular diffusivity, the

Fuller's equation used.

How long does it take for the partial pressure of n-butanol in the air vessel to reach 0.01 atm (in h)?

Hints for the second part:

- at any time point (so also at t= 0) forms the formula derived in the course for equimolar

counter-diffusion under steady state conditions is a good approximation for the occurring flux.

- at any time holds that c(butanol, vessel 1) = 31 mol/m3

- c(butanol, vessel 2) with the two concentrations in mol/m3

answer: t = 2.45 h