Chapter 15

Question 1

What is a nucleophile?

Answer 1

Negative ions (delta -ive charge) that donate a lone pair of electrons to form a new covalent bond. (Accepts an electron pair donor)

Question 2

What reaction do primary haloalkanes undergo and what are the conditions?

Answer 2

Hydrolysis by nucleophilic substitution - the halogen atom is replaced by an OH group to form an alcohol. Under reflux with NaOH.

Question 3

What does the rate of hydrolysis of a primary haloalkane depend on?

Answer 3

The strength of the C-halogen bond. Iodo is fastest as C-I bond is weakest and easier to break.

Question 4

Define the term radical.

Answer 4

Species with an unpaired electron.

Question 5

Why do CFC’s only break down in the stratosphere (upper atmosphere)?

Answer 5

Only UV in the upper atmosphere has enough energy to break the (C–Cl) bonds.

Question 6

Why is UV-B harmful?

Answer 6

Causes skin cancer and crop damage

Question 7

What is the equation for the steady state of ozone?

Answer 7

O2 + O* ⇌ O3

Question 8

What is the equation for the initiation of CFCl3?

Answer 8

CFCl3 -> CFCl2* + Cl*

Question 9

What are the two general propagation equations for the chlorine radical cycle?

Answer 9

1. X* + O3 –> XO* + O2
2. XO* + O –> X* + O2