Collision Theory Chemistry Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

hard
Two reactions have the same activation energy, but Reaction A involves small, linear molecules while Reaction B involves large, complex molecules. Using collision theory, predict which reaction has a higher proportion of effective collisions and explain why.

Solution

  1. 1
    Since both reactions have the same activation energy, the energy requirement is identical. The difference lies in the orientation factor.
  2. 2
    Small, linear molecules have simpler geometry, so a larger fraction of collisions will have the correct orientation for reaction. Large, complex molecules have more possible orientations, but only a few are correct.
  3. 3
    Therefore, Reaction A (small molecules) will have a higher proportion of effective collisions and a faster rate, all else being equal.

Answer

ReactionĀ AĀ ā€”Ā simplerĀ moleculesĀ haveĀ moreĀ favorableĀ orientationĀ probability.\text{Reaction A ā€” simpler molecules have more favorable orientation probability.}
The steric factor (orientation requirement) is an often-overlooked part of collision theory. Complex molecules must align precisely for reactive atoms to interact, which reduces the fraction of collisions that are effective.

About Collision Theory

A model explaining that chemical reactions occur only when reactant particles collide with sufficient kinetic energy (at least equal to the activation energy) and in.

Learn more about Collision Theory ā†’

More Collision Theory Examples

Example 1 easy

State the three conditions required for a successful chemical reaction according to collision theory

Example 2 medium

Use collision theory to explain why increasing the concentration of reactants increases the reaction

Example 3 medium

Using collision theory, explain why a finely ground powder reacts faster than a large chunk of the s

ā† All Collision Theory Examples Collision Theory Concept