Factors Affecting Rate

ChemistryAQAGCSEUnit: Rates of Reaction
Free taster
5 of 6 sections open
The basics

Controlling the Speed of Chemistry

๐Ÿ“– Controlling the Speed of Chemistry

Why do we refrigerate food? To slow down the chemical reactions that cause decay. Why do we use a catalyst in car exhausts? To speed up the breakdown of toxic gases. Every day, we control reaction rates without even thinking about it. Crushing a sugar cube makes it dissolve faster. Using hot water makes a stain easier to remove. These aren't random observations โ€” they're predictable consequences of collision theory. Once you understand WHY each factor works, you can predict and control reaction speeds in any situation.
๐Ÿณ The Cooking Analogy

Rate factors work just like cooking tips! Higher temperature (hot oven) = faster cooking. More concentration (more spice) = stronger reaction. Surface area (chopped vs whole veg) = faster cooking. Catalyst (pressure cooker) = speeds things up without being used up. Once you understand these principles, chemistry becomes as intuitive as cooking!

Spotlight
The Four Factors That Affect Rate

For gases: increasing PRESSURE has the same effect.

Exam tip

Earn the mark scheme marks

๐Ÿง  Memory Aid: CCTSP

Remember the five factors that affect rate of reaction using CCTSP:

  • C โ€” Concentration (more particles per volume)
  • C โ€” Catalyst (lowers activation energy)
  • T โ€” Temperature (faster particles, more exceed Ea)
  • S โ€” Surface area (more exposed particles)
  • P โ€” Pressure (for gases โ€” same as concentration)

Picture a chef (C) cooking (C) in the Test kitchen (T) with Special (S) Pans (P) โ€” CCTSP rules the kitchen of chemistry!

Now try it yourself

Quiz ยท Question 1 of 24

Which of the following factors does NOT affect the rate of a chemical reaction?

Tap an answer to check it

Revise every Chemistry topic, free during alpha

Factors Affecting Rate is one of 62 topics on PrepWise โ€” all aligned to your exam board.

Start revising free โ†’