Question

What do \((a)\) homogeneous reactions and \((b)\) heterogeneous reactions represent in mass transfer? To what do they correspond in heat transfer?

Short answer

Define homogeneous and heterogeneous reactions in mass transfer and their corresponding concepts in heat transfer.

Step-by-step solution

Define Homogeneous Reactions

In mass transfer, homogeneous reactions are those reactions where all the reactants and products are in the same phase (such as gas or liquid). These reactions occur throughout the entire volume of the reacting mixture, resulting in uniform local concentration.

Define Heterogeneous Reactions

Heterogeneous reactions, in contrast, involve reactants and products in different phases. These reactions occur at the interface between the phases, resulting in local concentration gradients. Common examples include solid-liquid and gas-liquid reactions.

Corresponding Concepts in Heat Transfer

In heat transfer, the concepts parallel to homogeneous and heterogeneous reactions are conduction and convection, respectively. In conduction, heat is transferred within a single phase (e.g., solid or fluid) by direct molecular interaction and temperature gradient. In convection, heat is transferred between different phases (e.g., solid and fluid) due to bulk motion of fluid particles, resulting in local temperature gradients similar to heterogeneous reactions in mass transfer.