9.3.2 Mechanism of Catalysis

• What is the role of a catalyst in catalysis?

  Speeds up reactions
• A catalyst speeds up a chemical reaction by lowering the activation energy
• Arrange the following phases of homogeneous and heterogeneous catalysts in increasing order of their interaction with reactants:

  1️⃣ Heterogeneous: Adsorption on solid surface

  2️⃣ Homogeneous: Intimate contact in liquid solution
• Homogeneous catalysts are typically in the solid phase.

  False
• Match the type of catalyst with its phase:

  Homogeneous catalyst ↔️ Liquid

  Heterogeneous catalyst ↔️ Solid
• What does a catalyst form temporary bonds with to lower activation energy?

  Reactants
• The catalyst works by lowering the activation energy
• What is the first step in the mechanism of catalysis?

  Adsorption
• Arrange the steps in the mechanism of catalysis in the correct order:

  1️⃣ Adsorption

  2️⃣ Reaction

  3️⃣ Desorption
• Match the type of catalyst with its example:

  Homogeneous catalyst ↔️ Acid-base catalyst

  Heterogeneous catalyst ↔️ Metal surface
• What is the primary function of a catalyst in terms of energy?

  Lower activation energy
• What is the phase of a homogeneous catalyst?

  Liquid
• What is the phase of a heterogeneous catalyst?

  Solid
• Homogeneous catalysts are in the same phase as the reactants
• Heterogeneous catalysts provide active sites on solid surfaces for reactions to occur.
• Match the feature with the type of catalyst:

  Same phase as reactants ↔️ Homogeneous catalyst

  Different phase from reactants ↔️ Heterogeneous catalyst
• Catalysts lower the activation energy ($E_{a}$), which in turn increases the reaction rate
• There are two main types of catalysts: homogeneous and heterogeneous.
• Match the type of catalyst with its definition:

  Homogeneous Catalysts ↔️ Present in the same phase as reactants

  Heterogeneous Catalysts ↔️ Exist in a different phase from reactants
• How do catalysts enable more molecules to overcome the reaction barrier?

  By lowering $E_{a}$
• Homogeneous catalysts are typically in the liquid phase, allowing for intimate interaction with reactants.
• In what phase do heterogeneous catalysts typically exist?

  Solid
• Match the feature with the correct type of catalyst:

  Homogeneous Catalyst ↔️ Same phase as reactants

  Heterogeneous Catalyst ↔️ Different phase from reactants
• Homogeneous catalysts exist in the same phase as the reactants.
• Heterogeneous catalysts are easier to separate from reaction mixtures than homogeneous catalysts.
• What is an example of homogeneous catalysis?

  Acid-catalyzed ester hydrolysis
• In the Haber-Bosch process, nitrogen and hydrogen react using iron as a catalyst.
• Steps in the mechanism of catalysis:

  1️⃣ Adsorption of reactants on the catalyst surface

  2️⃣ Chemical transformation of reactants

  3️⃣ Desorption of products from the surface
• What role does the iron catalyst play in the Haber-Bosch process?

  Lowers activation energy
• Catalysts are consumed during the reaction.

  False
• A larger surface area in heterogeneous catalysts increases the number of active sites.
• Match the catalytic reaction with its catalyst:

  Homogeneous Catalysis ↔️ Sulfuric Acid

  Heterogeneous Catalysis ↔️ Platinum