Free radical substitution

Question 1

What initiates a free radical substitution reaction?

Answer 1

UV light

Question 2

Why does the Cl-Cl bond break when exposed to UV light?

Answer 2

The Cl molecule absorbs the energy of a quantum of UV light. The energy of one quantum is greater than the Cl-Cl bond energy, so the bond will break

Question 3

What is a free radical?

Answer 3

A highly reactive chemical species with an unpaired electron

Question 4

What is the name of the process of the halogen-halogen bond breaking in the initiation stage of free radical substitution?

Answer 4

Homolytic fission

Question 5

Why is only the halogen-halogen bond that breaks when a haloalkane is exposed to UV light?

Answer 5

The C-H bond is stronger than the energy in one quantum of UV light

Question 6

Why are more isomers produced in a free radical substitution reaction involving a long chain haloalkane?

Answer 6

The halogen free radical can replace any hydrogen atom

Question 7

What is the molecular formula of ozone?

Answer 7

O₃

Question 8

What is the equation for the decompositon of ozone?

Answer 8

2O_{3 ——>} 3O₂

Question 9

What are the 2 propagation reactions to form CH₃Cl from chlorine and methane?

Answer 9

Cl• + CH₄ —–> HCl + •CH₃

•CH₃ + Cl₂ —–> CH₃Cl + Cl•

Question 10

What are the 2 propagation reactions in the decompositon of ozone?

Answer 10

Cl• + O₃ —–> ClO• + O₂

ClO• + O₃ —–> 2O₂ + Cl•