Skip to content
Dabour HubLEARN · PRACTICE · EXPLORESign inStudent

9.2.5Metals

Catalysts — Cambridge IGCSE Chemistry 0620 Revision Notes & Topical Questions

5 min read 4 parts Lesson 7 of 8 Unit quiz

📚 Cambridge IGCSE Chemistry 0620 Hub / Topical Revision
🩺
100% Curriculum Specification Match Lesson Doctor Verified
The only platform with 100% curriculum specification match and verified interactive question banks.
0%read

Part 1 of 4How Catalysts Work

9.2.5 Catalysts

A catalyst gives the reaction a different route with a lower energy barrier.

Pathway
  • A catalyst provides the reactants with a different pathway that has a lower activation energy.
Effective collisions
  • A greater proportion of the particles have enough energy for an effective collision.
Rate
  • The catalysed reaction is faster than the uncatalysed reaction at the same temperature.
Energy change
  • A catalyst does not change the overall energy change, ΔH, of the reaction.

Part 2 of 4Drawing the Energy Level Diagram

Both curves on the diagram share the same starting and finishing levels.

1
Draw the uncatalysed curve for an exothermic reaction with its usual activation energy peak.
2
Draw a second, lower curve for the catalysed reaction, which starts and finishes at the same energy levels.
3
Label the lower peak with the new, smaller activation energy.
4
Keep the reactant and product levels the same, because the overall energy change is unchanged.

Part 3 of 4Catalysts in Industry

Catalysts make industrial processes faster and cheaper.

Catalysts in Industry
Lower temperature
  • A catalyst allows a reaction to run at a lower temperature, which saves energy.
Haber process
  • An iron catalyst speeds up the production of ammonia from nitrogen and hydrogen.
Contact process
  • Vanadium(V) oxide speeds up the oxidation of sulfur dioxide to sulfur trioxide.
Cost
  • Catalysts reduce energy and running costs, which makes industrial processes more economic.

Part 4 of 4Exam Checklist & Tips

9.2.5 – Key Points for the Exam

  • Catalyst A substance that speeds up a reaction and is chemically unchanged at the end.
  • Activation energy The minimum energy needed for particles to react when they collide.
  • Alternative pathway A different route for a reaction that has a lower activation energy.
  • Effective collision A collision with enough energy to produce a reaction.

Common Mistakes

  • Drawing the catalysed curve with a different start or end point from the uncatalysed curve.
  • Saying a catalyst changes the overall energy change of the reaction.
  • Stating that a catalyst is used up during the reaction.
  • Confusing the height of the peak with the energy change; the peak height is the activation energy.

Last updated:

\n