Homogeneous vs. heterogeneous catalysts

• What type of catalyst is amylase?

  It is an enzyme catalyst
• What reactant does amylase catalyze?

  Starch
• What is the significance of a homogeneous catalyst being in the same phase as reactants?

  It enhances mixing and interaction efficiency
• What is the general characteristic of heterogeneous catalysts in terms of phase?

  • They are solids
  • Reactants are typically liquids or gases
  • They facilitate reactions without being consumed
• How does the efficiency of homogeneous catalysts compare to heterogeneous catalysts?

  Homogeneous catalysts are highly efficient
• How does a heterogeneous catalyst work?

  • Provides a solid surface for reactants
  • Reactants are adsorbed onto the catalyst surface
  • Chemical bonds break/form at active sites
  • New products are released from the surface
  • Catalyst remains unchanged
• How does a heterogeneous catalyst differ from a homogeneous catalyst?

  Heterogeneous catalysts have different phases than reactants
• What type of reaction does platinum (Pt) catalyze?

  Hydrogenation of alkenes
• What type of catalyst is ZSM-5?

  A zeolite used for cracking hydrocarbons
• What is the role of iron oxide (Fe₂O₃) in the Haber process?

  It acts as a catalyst for ammonia synthesis
• How do homogeneous catalysts react?

  They react in solution
• What is a heterogeneous catalyst?

  A catalyst that is in a different phase than reactants
• How does the reaction rate of homogeneous catalysts compare to heterogeneous catalysts?

  Homogeneous catalysts are typically faster
• What is the name of the surface shown in the image?

  Catalyst Surface
• How do heterogeneous catalysts react?

  They react on a surface
• Why can separation of homogeneous catalysts be difficult?

  They are in the same phase as reactants
• What is the name of the molecule shown in part (d) of the image?

  Ethane
• In what phase is amylase as a catalyst?

  Liquid
• What is the purpose of the catalyst surface shown in the image?

  • To facilitate chemical reactions
  • To increase the rate of reactions
  • To lower the activation energy of reactions
• Why might heterogeneous catalysts have lower efficiency?

  Due to surface reactions limiting effectiveness
• What is the analogy used to explain a homogeneous catalyst?

  • A special helper in baking
  • Mixing ingredients like flour and sugar
  • Catalyst is like honey mixing well
  • Helps ingredients react faster
• What is a key advantage of homogeneous catalysts?

  Higher efficiency and faster reaction rates
• Why is separation of heterogeneous catalysts easy?

  They are in a different phase from reactants
• What is a homogeneous catalyst?

  A catalyst that is in the same phase
• What product is formed when amylase catalyzes starch?

  Glucose
• What is a homogeneous catalyst?

  A substance that speeds up a reaction
• How does the catalyst surface interact with the molecules shown in the image?

  • The catalyst surface provides a surface for the molecules to adsorb onto
  • This increases the probability of collisions between the molecules
  • The catalyst lowers the activation energy required for the reaction to occur
• What products are formed when sulfuric acid (H₂SO₄) catalyzes esters and water?

  Alcohols and carboxylic acids
• What reactants does sodium hydroxide (NaOH) catalyze?

  Ketones
• Why does a homogeneous catalyst allow for efficient interaction with reactants?

  Because they mix easily in the same phase
• What is a key advantage of heterogeneous catalysts?

  Easy to separate from products
• In what phase is sulfuric acid (H₂SO₄) as a catalyst?

  Liquid
• How does a homogeneous catalyst interact with reactants?

  It is in the same phase as the reactants
• In what phase is sodium hydroxide (NaOH) as a catalyst?

  Liquid
• What is a heterogeneous catalyst?

  A catalyst providing a solid surface for reactions
• How do the catalyst surface and the molecules shown in the image differ in their structures?

  The catalyst surface is a solid, while the molecules are gases or liquids
• What reactants does sulfuric acid (H₂SO₄) catalyze?

  Esters and water
• In what scenario would you use a homogeneous catalyst?

  When all reactants are in the same phase
• How does the cost of homogeneous catalysts compare to heterogeneous catalysts?

  Homogeneous catalysts are generally more expensive
• What is the phase of homogeneous catalysts?

  Same phase as reactants