homogeneous and heterogeneous reaction

[Melissa Rojas]

in the most simplest terms may someone please explain to me the main difference between a homogeneous and heterogeneous reaction, and how does it affect the reaction kinetics? I keep getting these confused...

[Gauri Gusain 3H]

All the reactants and products are in the same phase for homogeneous, for example, everything is in the gas phase or everything is in the aqueous phase, and they are not in the same phase for heterogeneous. This means that there can be reactants and products in the gas and aq phase for example. The different phases do not affect kinetic rates. You would calculate the rate for both of them in the same way. In general, however, gaseous reactants react the fastest because they have higher energy because of their random movement so that they can easily cross the energy barrier that separates the reactants from the products and gases can easily be adsorbed on the surface of the catalyst so that the reaction proceeds with a fast rate.

[Josie Rose 1E]

Homogenous reactions have both the reactant and products in the same phase (solid/liquid/gas) and heterogenous reactions mix between the phases.

[Tiana_Gregoryona_1L]

Hello! The terms homogeneous and heterogeneous actually are in reference to catalysis. A homogeneous catalyst is in the same phase as the reactants (think of the root word "homo" which means "same" or "alike") where as a heterogeneous catalyst is not in the same phase as the reactants (think of the root word "hetero" which means "different"). Hopefully knowing the meanings of the root terms helps!

[Leily Garcia 1C]

A homogeneous reaction is one that occurs uniformly through a given phase. In contrast, a heterogeneous reaction takes place in a restricted region or within the boundary of a phase. A reaction is said to be the first order if the rate of reaction is directly proportional to the concentration itself.