Question

The hydrogenation of unsaturated hydrocarbons is an important industrial process. Precious metals, such as platinum and palladium, can greatly increase the rate of this reaction. During this process, the gaseous reactants are pumped across a layer of metal powder. An example of this process is shown below. Hydrogenation on catalyst Describe how the metal probably increases the reaction rate, identify whether this is an example of homogeneous or heterogeneous catalysis, and explain how you know.

Which of the following did your answer include?
a) The metal probably increases reaction rate by either holding reactant molecules in the correct orientation to react or by weakening or breaking bonds in reactant molecules to make them more reactive.
b) This is an example of heterogeneous catalysis.
c) It is heterogeneous catalysis because the catalyst is a solid and the reactants are gases.
d) In heterogeneous catalysis, the catalyst is in a different phase than the reactants.

Answer 1

The precious metal catalysts, platinum and palladium, increase the rate of the hydrogenation reaction by holding the reactant molecules in the correct orientation or weakening/breaking their bonds. This is an example of heterogeneous catalysis because the metal catalyst is a solid and the reactants are gases.

Step-by-step explanation:

In the hydrogenation of unsaturated hydrocarbons, the precious metals platinum and palladium act as catalysts, increasing the rate of the reaction. The metal catalysts can either hold the reactant molecules in the correct orientation for reaction or weaken/break the bonds in the reactant molecules, making them more reactive.

This is an example of heterogeneous catalysis, as the catalyst (metal powder) is in a different phase than the reactants (gaseous). In heterogeneous catalysis, the catalyst is typically a solid while the reactants can be gases or liquids.