Consider liquid n-hexane in a 50-mm diameter graduated cylinder. Air blows across the top of the cylinder. The distance from the liquid-gas interface to the top of the cylinder is 20 cm. Assume the diffusivity of n-hexane is 8.8.10^-6 m^2/s. The liquid n-hexane is at 25°C. Estimate the evaporation rate of the nhexane.

The evaporation rate of the n-Hexane is

Explanation:

This is a situation regarding diffusing A through non-diffusing B.

A = n-Hexane B=Air

Where the molar flux is provided by,

the vapor pressure at hexane

For wind, assume negligible hexane is present, hence

Now,

where T = 298 K

substituting all in the equation, we get

Now,Flux area  = Molar rate of evaporation

Evaporation rate =

Evaporation rate =