Rates of reaction

Traps in Rates of reaction

• Uses everyday or macroscopic thinking instead of particles
  Ask what the particles, ions or electrons are doing. Properties of a substance come from its particles and bonds, not from how it looks or feels.
• Picks a related substance or process with a different role
  Learn reagents and processes as one-line 'name → job' cards and contrast neighbours in a table (process | product | catalyst | conditions). Match the job in the stem, not just the topic.
• Reverses a trend, direction or effect
  State the rule with its direction before looking at the options (down group 1 reactivity INCREASES; exothermic forward reaction: heating shifts LEFT). An option that is the mirror image of the rule is the trap.
• Chooses a true but irrelevant statement
  Re-read the question word (why, which, what causes). A true fact that answers a different question is still wrong.
• Mixes up a pair of similar chemical terms
  Keep a list of confusable pairs with one defining feature each and a hook. Underline the key word in the stem and check it against the definition, not the sound of the name.
• Thinks a catalyst shifts equilibrium, adds energy or is used up
  A catalyst gives an alternative route with lower activation energy for BOTH directions. It is unchanged at the end, so it changes the rate only: never the yield, ΔH or Kc.
• Uses the wrong arithmetic operation
  Write the relationship in words before substituting (crystals = solubility at high T − solubility at low T; neutrons = A − Z; three doublings = 2³). Then check the size of the answer.