(Mass transfer). Pure water at atmospheric pressure and 300 K temperature flows in a circular tube with a diameter of 3 mm, with a mean velocity of 2 cm/s. The tube wall is made of a substance that is...

(Mass transfer). Pure water at atmospheric pressure and 300 K temperature flows in a circular tube with a diameter of 3 mm, with a mean velocity of 2 cm/s. The tube wall is made of a substance that is sparingly soluble in water. The dissolution of the wall material (the transferred species) takes place such that the mass fraction of the transferred species at the wall surface remains constant at 5 × 10⁻⁴
. The mass transfer properties of the transferred species are assumed to be similar to CO₂

a. Can we assume developed conditions with respect to mass transfer at 0.1 m and 0.5 m downstream from inlet?

b. Assuming developed flow conditions at 0.5 m downstream from inlet, calculate the local mass transfer coefficient.

 c. Estimate the effect of axial mass diffusion in the fluid on the mass transfer coefficient in Part b.