Mass Transfer - Engineering

Q1:

The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which D is the diffusivity of solute, is

A D/a

B D/2a

C proportional to D

D dependent on the Reynolds number

ANS:D - dependent on the Reynolds number

The mass transfer coefficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid is proportional to the diffusivity of the solute (D) and the inverse of the characteristic length scale (a), which is the radius of the sphere. Therefore, the mass transfer coefficient (𝑘k) can be expressed as: k=a/D​ So, the correct option is: a/D​