haloalkanes

Question 1

condition for free radical substitution

Answer 1

UV light (needed to break bond between halogen atoms, to from halogen radicals)

Question 2

condition to ensure further substitution in free radical substitution

Answer 2

excess halogen

Question 3

condition to prevent further substitution in free radical substitution

Answer 3

excess alkane

Question 4

define free radical

Answer 4

reactive species due to unpaired electron

Question 5

equations for decomposition of ozone by chlorine radicals

Answer 5

R-Cl → R* + Cl*
Cl* + O₃ → ClO* + O₂
ClO* + O₃ → Cl* + 2O₂

Question 6

overall equation for decomposition of ozone

Answer 6

2O₃ → 3O₂

Question 7

explain how Cl* acts as catalysts in breakdown of ozone

Answer 7

Cl* is regenerated

Question 8

describe alternatives to CFCs

Answer 8

-chlorine-free compounds
-only contains C-H and C-F bonds which are stronger than C-Cl bonds so don’t break in UV light

Question 9

equation for reaction between bromoethane and excess ammonia

Answer 9

CH₃CH₂Br + 2NH₃ → CH₃CH₂NH₂ + NH₄Br

Question 10

what does OH⁻ acts as in elimination with haloalkane

Answer 10

base