Horrocks L8

Question 1

How do we analyse reaction mechanisms

Answer 1

integration of rate law
Steady-state approximation
Numerical methods

Question 2

Where are chain mechanisms used

Answer 2

radical polymerisation
Nuclear fission
Photochemistry
Atmospheric chemistry

Question 3

What is a branching chain mechanism

Answer 3

A branching chain mechanism is where the reaction can branch out at certain points, leading to an exponential increase in the number of active reaction species. This branching behavior enhances the propagation of the reaction, which can result in a much faster and sometimes explosive reaction rate

Question 4

What is the simplified rate law for branching chain mechanisms

Answer 4

r˙ = kbrr − ktr + ki
r is the overall chain carrier (radical) concentration kbr, kt and ki are
overall pseudo rate constants for the branching, termination and initiation processes

Question 5

what are the two basic kinds of chemical explosions

Answer 5

thermal explosions and chain branching explosions

Question 6

Describe Thermal explosions

Answer 6

occur when heat is released by a reaction morerapidly than it can escape from the reaction space. This causes the reaction to proceed more rapidly, releasing even more heat

Question 7

What is chain branching explosions

Answer 7

Chain-branching explosions occur when the number of chain carriers
increases exponentially.

Question 8

What is a BZ reaction

Answer 8

The BZ reaction is a redox reaction involving an organic substrate, an oxidizing agent, and a metal ion catalyst. It occurs in an acidic solution.