Rate Laws

Question 1

Steady state approximation

Answer 1

Reactive intermediate conc stays much smaller than other reactants/products so rate of change of conc is so small comparatively it can be set to 0

Question 2

Lindemann-Hinshelwood Mechanism

Answer 2

A energetically excited through collision with another A: A+A -> A* + A (k1)
KE of collision from internal vibrational energy (3N-5/3N-6 if linear)
A* energy distributed through all vibrational modes but only one contributed to reaction coordinate
Time taken for E>Ea to randomly accumulate in right vibrational mode then A* -> P (k2)
A* can also lose energy by k1’
Overall rate = K2[A*]

Question 3

Inert collision partner

Answer 3

Inert molecule M = third body